diff --git a/lib/encryption/key_manager.dart b/lib/encryption/key_manager.dart
index 64e407c1..2aefd18d 100644
--- a/lib/encryption/key_manager.dart
+++ b/lib/encryption/key_manager.dart
@@ -69,11 +69,14 @@ class KeyManager {
         if (lastEvent != null &&
             lastEvent.type == EventTypes.Encrypted &&
             lastEvent.content['can_request_session'] == true) {
-          try {
-            maybeAutoRequest(room.id, lastEvent.content['session_id'] as String,
-                lastEvent.content['sender_key'] as String?);
-          } catch (_) {
-            // dispose
+          final sessionId = lastEvent.content.tryGet<String>('session_id');
+          final senderKey = lastEvent.content.tryGet<String>('sender_key');
+          if (sessionId != null && senderKey != null) {
+            maybeAutoRequest(
+              room.id,
+              sessionId,
+              senderKey,
+            );
           }
         }
       }
@@ -647,16 +650,16 @@ class KeyManager {
           } catch (e, s) {
             Logs().e('[LibOlm] Error decrypting room key', e, s);
           }
-          if (decrypted != null) {
+          final senderKey = decrypted?.tryGet<String>('sender_key');
+          if (decrypted != null && senderKey != null) {
             decrypted['session_id'] = sessionId;
             decrypted['room_id'] = roomId;
             await setInboundGroupSession(
-                roomId, sessionId, decrypted['sender_key'] as String, decrypted,
+                roomId, sessionId, senderKey, decrypted,
                 forwarded: true,
-                senderClaimedKeys: decrypted['sender_claimed_keys']
-                        is Map<String, String>
-                    ? (decrypted['sender_claimed_keys'] as Map<String, String>)
-                    : <String, String>{},
+                senderClaimedKeys: decrypted
+                        .tryGetMap<String, String>('sender_claimed_keys') ??
+                    <String, String>{},
                 uploaded: true);
           }
         }
@@ -833,14 +836,24 @@ class KeyManager {
         Logs().i(
             '[KeyManager] Received key sharing request from ${event.sender}:${event.content['requesting_device_id']}...');
         if (!event.content.containsKey('body')) {
-          Logs().i('[KeyManager] No body, doing nothing');
+          Logs().w('[KeyManager] No body, doing nothing');
           return; // no body
         }
-        final body = event.content['body'] as Map<String, Object?>;
+        final body = event.content.tryGetMap<String, Object?>('body');
+        if (body == null) {
+          Logs().w('[KeyManager] Wrong type for body, doing nothing');
+          return; // wrong type for body
+        }
+        final roomId = body.tryGet<String>('room_id');
+        if (roomId == null) {
+          Logs().w(
+              '[KeyManager] Wrong type for room_id or no room_id, doing nothing');
+          return; // wrong type for roomId or no roomId found
+        }
         final device = client.userDeviceKeys[event.sender]
             ?.deviceKeys[event.content['requesting_device_id']];
         if (device == null) {
-          Logs().i('[KeyManager] Device not found, doing nothing');
+          Logs().w('[KeyManager] Device not found, doing nothing');
           return; // device not found
         }
         if (device.userId == client.userID &&
@@ -848,16 +861,15 @@ class KeyManager {
           Logs().i('[KeyManager] Request is by ourself, ignoring');
           return; // ignore requests by ourself
         }
-        if (body['room_id'] is! String) {
-          return; // wrong type for room_id
-        }
-        final room = client.getRoomById(body['room_id'] as String);
+        final room = client.getRoomById(roomId);
         if (room == null) {
           Logs().i('[KeyManager] Unknown room, ignoring');
           return; // unknown room
         }
-        final sessionId = body['session_id'];
-        if (sessionId is! String) {
+        final sessionId = body.tryGet<String>('session_id');
+        if (sessionId == null) {
+          Logs().w(
+              '[KeyManager] Wrong type for session_id or no session_id, doing nothing');
           return; // wrong type for session_id
         }
         // okay, let's see if we have this session at all
@@ -867,10 +879,12 @@ class KeyManager {
           return; // we don't have this session anyways
         }
         if (event.content['request_id'] is! String) {
+          Logs().w(
+              '[KeyManager] Wrong type for request_id or no request_id, doing nothing');
           return; // wrong type for request_id
         }
         final request = KeyManagerKeyShareRequest(
-          requestId: event.content['request_id'] as String,
+          requestId: event.content.tryGet<String>('request_id')!,
           devices: [device],
           room: room,
           sessionId: sessionId,
@@ -890,7 +904,7 @@ class KeyManager {
           await roomKeyRequest.forwardKey();
         } else if (device.encryptToDevice &&
             session.allowedAtIndex
-                    .tryGet<Map<String, dynamic>>(device.userId)
+                    .tryGet<Map<String, Object?>>(device.userId)
                     ?.tryGet(device.curve25519Key!) !=
                 null) {
           // if we know the user may see the message, then we can just forward the key.
@@ -946,6 +960,7 @@ class KeyManager {
       (event.content['forwarding_curve25519_key_chain'] as List)
           .add(encryptedContent['sender_key']);
       if (event.content['sender_claimed_ed25519_key'] is! String) {
+        Logs().w('sender_claimed_ed255519_key has wrong type');
         return; // wrong type
       }
       // TODO: verify that the keys work to decrypt a message
@@ -987,8 +1002,13 @@ class KeyManager {
         Logs().v('[KeyManager] not encrypted, ignoring...');
         return; // the event wasn't encrypted, this is a security risk;
       }
-      final String roomId = event.content['room_id'] as String;
-      final String sessionId = event.content['session_id'] as String;
+      final roomId = event.content.tryGet<String>('room_id');
+      final sessionId = event.content.tryGet<String>('session_id');
+      if (roomId == null || sessionId == null) {
+        Logs().w(
+            'Either room_id or session_id are not the expected type or missing');
+        return;
+      }
       final sender_ed25519 = client.userDeviceKeys[event.sender]
           ?.deviceKeys[event.content['requesting_device_id']]?.ed25519Key;
       if (sender_ed25519 != null) {
diff --git a/lib/encryption/olm_manager.dart b/lib/encryption/olm_manager.dart
index 5d53441a..054aa850 100644
--- a/lib/encryption/olm_manager.dart
+++ b/lib/encryption/olm_manager.dart
@@ -598,35 +598,34 @@ class OlmManager {
         final identityKey =
             client.userDeviceKeys[userId]!.deviceKeys[deviceId]!.curve25519Key;
         for (final deviceKey in deviceKeysEntry.value.values) {
-          if (deviceKey is Map<String, Object?>) {
-            if (fingerprintKey == null ||
-                identityKey == null ||
-                !deviceKey.checkJsonSignature(
-                    fingerprintKey, userId, deviceId)) {
-              Logs().w(
-                'Skipping invalid device key from $userId:$deviceId',
-                deviceKey,
-              );
-              continue;
-            }
-            Logs().v('[OlmManager] Starting session with $userId:$deviceId');
-            final session = olm.Session();
-            try {
-              session.create_outbound(
-                  _olmAccount!, identityKey, deviceKey['key'] as String);
-              await storeOlmSession(OlmSession(
-                key: client.userID!,
-                identityKey: identityKey,
-                sessionId: session.session_id(),
-                session: session,
-                lastReceived:
-                    DateTime.now(), // we want to use a newly created session
-              ));
-            } catch (e, s) {
-              session.free();
-              Logs().e(
-                  '[LibOlm] Could not create new outbound olm session', e, s);
-            }
+          if (fingerprintKey == null ||
+              identityKey == null ||
+              deviceKey is! Map<String, Object?> ||
+              !deviceKey.checkJsonSignature(fingerprintKey, userId, deviceId) ||
+              deviceKey['key'] is! String) {
+            Logs().w(
+              'Skipping invalid device key from $userId:$deviceId',
+              deviceKey,
+            );
+            continue;
+          }
+          Logs().v('[OlmManager] Starting session with $userId:$deviceId');
+          final session = olm.Session();
+          try {
+            session.create_outbound(
+                _olmAccount!, identityKey, deviceKey.tryGet<String>('key')!);
+            await storeOlmSession(OlmSession(
+              key: client.userID!,
+              identityKey: identityKey,
+              sessionId: session.session_id(),
+              session: session,
+              lastReceived:
+                  DateTime.now(), // we want to use a newly created session
+            ));
+          } catch (e, s) {
+            session.free();
+            Logs()
+                .e('[LibOlm] Could not create new outbound olm session', e, s);
           }
         }
       }
diff --git a/lib/encryption/ssss.dart b/lib/encryption/ssss.dart
index 1a20abb0..e6dab387 100644
--- a/lib/encryption/ssss.dart
+++ b/lib/encryption/ssss.dart
@@ -280,8 +280,7 @@ class SSSS {
   }
 
   bool isSecret(String type) =>
-      client.accountData[type] != null &&
-      client.accountData[type]!.content['encrypted'] is Map;
+      client.accountData[type]?.content['encrypted'] is Map;
 
   Future<String?> getCached(String type) async {
     if (client.database == null) {
@@ -295,9 +294,11 @@ class SSSS {
     bool isValid(SSSSCache dbEntry) =>
         keys.contains(dbEntry.keyId) &&
         dbEntry.ciphertext != null &&
-        ((client.accountData[type]?.content['encrypted']
-                    as Map<String, Object?>)[dbEntry.keyId]
-                as Map<String, Object?>)['ciphertext'] ==
+        dbEntry.keyId != null &&
+        client.accountData[type]?.content
+                .tryGetMap<String, Object?>('encrypted')
+                ?.tryGetMap<String, Object?>(dbEntry.keyId!)
+                ?.tryGet<String>('ciphertext') ==
             dbEntry.ciphertext;
 
     final fromCache = _cache[type];
@@ -320,25 +321,31 @@ class SSSS {
     if (secretInfo == null) {
       throw Exception('Not found');
     }
-    if (secretInfo.content['encrypted'] is! Map) {
+    final encryptedContent =
+        secretInfo.content.tryGetMap<String, Object?>('encrypted');
+    if (encryptedContent == null) {
       throw Exception('Content is not encrypted');
     }
-    if ((secretInfo.content['encrypted'] as Map<String, Object?>)[keyId]
-        is! Map) {
+    final enc = encryptedContent.tryGetMap<String, Object?>(keyId);
+    if (enc == null) {
       throw Exception('Wrong / unknown key');
     }
-    final enc = (secretInfo.content['encrypted'] as Map<String, Object?>)[keyId]
-        as Map<String, Object?>;
+    final ciphertext = enc.tryGet<String>('ciphertext');
+    final iv = enc.tryGet<String>('iv');
+    final mac = enc.tryGet<String>('mac');
+    if (ciphertext == null || iv == null || mac == null) {
+      throw Exception('Wrong types for encrypted content or missing keys.');
+    }
     final encryptInfo = EncryptedContent(
-        iv: enc['iv'] as String,
-        ciphertext: enc['ciphertext'] as String,
-        mac: enc['mac'] as String);
+      iv: iv,
+      ciphertext: ciphertext,
+      mac: mac,
+    );
     final decrypted = await decryptAes(encryptInfo, key, type);
     final db = client.database;
     if (cacheTypes.contains(type) && db != null) {
       // cache the thing
-      await db.storeSSSSCache(
-          type, keyId, enc['ciphertext'] as String, decrypted);
+      await db.storeSSSSCache(type, keyId, ciphertext, decrypted);
       onSecretStored.add(keyId);
       if (_cacheCallbacks.containsKey(type) && await getCached(type) == null) {
         _cacheCallbacks[type]!(decrypted);
@@ -388,11 +395,14 @@ class SSSS {
     if (content == null) {
       throw InvalidPassphraseException('Key has no content!');
     }
-    final contentEncrypted = content['encrypted'] as Map<String, Object?>;
+    final encryptedContent = content.tryGetMap<String, Object?>('encrypted');
+    if (encryptedContent == null) {
+      throw Exception('Wrong type for encrypted content!');
+    }
 
     final otherKeys =
-        Set<String>.from(contentEncrypted.keys.where((k) => k != keyId));
-    contentEncrypted.removeWhere((k, v) => otherKeys.contains(k));
+        Set<String>.from(encryptedContent.keys.where((k) => k != keyId));
+    encryptedContent.removeWhere((k, v) => otherKeys.contains(k));
     // yes, we are paranoid...
     if (await getStored(type, keyId, key) != secret) {
       throw Exception('Secrets do not match up!');
@@ -401,8 +411,12 @@ class SSSS {
     await client.setAccountData(client.userID!, type, content);
     if (cacheTypes.contains(type)) {
       // cache the thing
-      final ciphertext = (contentEncrypted[keyId]
-          as Map<String, Object?>)['ciphertext'] as String;
+      final ciphertext = encryptedContent
+          .tryGetMap<String, Object?>(keyId)
+          ?.tryGet<String>('ciphertext');
+      if (ciphertext == null) {
+        throw Exception('Wrong type for ciphertext!');
+      }
       await client.database?.storeSSSSCache(type, keyId, ciphertext, secret);
       onSecretStored.add(keyId);
     }
@@ -509,8 +523,12 @@ class SSSS {
         return; // nope....unknown or untrusted device
       }
       // alright, all seems fine...let's check if we actually have the secret they are asking for
-      final type = event.content['name'];
-      final secret = await getCached(type as String);
+      final type = event.content.tryGet<String>('name');
+      if (type == null) {
+        Logs().i('[SSSS] Wrong data type for type param, ignoring');
+        return;
+      }
+      final secret = await getCached(type);
       if (secret == null) {
         Logs()
             .i('[SSSS] We don\'t have the secret for $type ourself, ignoring');
@@ -544,11 +562,11 @@ class SSSS {
         Logs().i('[SSSS] Someone else replied?');
         return; // someone replied whom we didn't send the share request to
       }
-      if (event.content['secret'] is! String) {
+      final secret = event.content.tryGet<String>('secret');
+      if (secret == null) {
         Logs().i('[SSSS] Secret wasn\'t a string');
         return; // the secret wasn't a string....wut?
       }
-      final secret = event.content['secret'] as String;
       // let's validate if the secret is, well, valid
       if (_validators.containsKey(request.type) &&
           !(await _validators[request.type]!(secret))) {
@@ -565,9 +583,14 @@ class SSSS {
       if (db != null) {
         final keyId = keyIdFromType(request.type);
         if (keyId != null) {
-          final ciphertext = ((client.accountData[request.type]!
-                  .content['encrypted'] as Map<String, Object?>)[keyId]
-              as Map<String, Object?>)['ciphertext'] as String;
+          final ciphertext = (client.accountData[request.type]!.content
+                  .tryGetMap<String, Object?>('encrypted'))
+              ?.tryGetMap<String, Object?>(keyId)
+              ?.tryGet<String>('ciphertext');
+          if (ciphertext == null) {
+            Logs().i('[SSSS] Ciphertext is empty or not a String');
+            return;
+          }
           await db.storeSSSSCache(request.type, keyId, ciphertext, secret);
           if (_cacheCallbacks.containsKey(request.type)) {
             _cacheCallbacks[request.type]!(secret);
@@ -583,8 +606,10 @@ class SSSS {
     if (data == null) {
       return null;
     }
-    if (data.content['encrypted'] is Map) {
-      return (data.content['encrypted'] as Map<String, Object?>).keys.toSet();
+    final contentEncrypted =
+        data.content.tryGetMap<String, Object?>('encrypted');
+    if (contentEncrypted != null) {
+      return contentEncrypted.keys.toSet();
     }
     return null;
   }
diff --git a/lib/encryption/utils/bootstrap.dart b/lib/encryption/utils/bootstrap.dart
index 34d366c0..dc728b63 100644
--- a/lib/encryption/utils/bootstrap.dart
+++ b/lib/encryption/utils/bootstrap.dart
@@ -104,13 +104,14 @@ class Bootstrap {
     for (final entry in client.accountData.entries) {
       final type = entry.key;
       final event = entry.value;
-      if (event.content['encrypted'] is! Map) {
+      final encryptedContent =
+          event.content.tryGetMap<String, Object?>('encrypted');
+      if (encryptedContent == null) {
         continue;
       }
       final validKeys = <String>{};
       final invalidKeys = <String>{};
-      for (final keyEntry
-          in (event.content['encrypted'] as Map<String, Object?>).entries) {
+      for (final keyEntry in encryptedContent.entries) {
         final key = keyEntry.key;
         final value = keyEntry.value;
         if (value is! Map) {
diff --git a/lib/msc_extensions/msc_3814_dehydrated_devices/api.dart b/lib/msc_extensions/msc_3814_dehydrated_devices/api.dart
index 4e709e7b..1f4b262a 100644
--- a/lib/msc_extensions/msc_3814_dehydrated_devices/api.dart
+++ b/lib/msc_extensions/msc_3814_dehydrated_devices/api.dart
@@ -48,7 +48,8 @@ extension DehydratedDeviceMatrixApi on MatrixApi {
       },
     );
     return Map<String, int>.from(
-        response['one_time_key_counts'] as Map<String, Object?>);
+        response.tryGetMap<String, Object?>('one_time_key_counts') ??
+            <String, int>{});
   }
 
   /// uploads a dehydrated device.
diff --git a/lib/src/client.dart b/lib/src/client.dart
index 28582646..e21458a3 100644
--- a/lib/src/client.dart
+++ b/lib/src/client.dart
@@ -298,7 +298,7 @@ class Client extends MatrixApi {
     final ruleset = TryGetPushRule.tryFromJson(
         _accountData[EventTypes.PushRules]
                 ?.content
-                .tryGetMap<String, dynamic>('global') ??
+                .tryGetMap<String, Object?>('global') ??
             {});
     _pushruleEvaluator = PushruleEvaluator.fromRuleset(ruleset);
   }
@@ -1068,7 +1068,7 @@ class Client extends MatrixApi {
   PushRuleSet? get globalPushRules {
     final pushrules = _accountData['m.push_rules']
         ?.content
-        .tryGetMap<String, dynamic>('global');
+        .tryGetMap<String, Object?>('global');
     return pushrules != null ? TryGetPushRule.tryFromJson(pushrules) : null;
   }
 
@@ -1076,7 +1076,7 @@ class Client extends MatrixApi {
   PushRuleSet? get devicePushRules {
     final pushrules = _accountData['m.push_rules']
         ?.content
-        .tryGetMap<String, dynamic>('device');
+        .tryGetMap<String, Object?>('device');
     return pushrules != null ? TryGetPushRule.tryFromJson(pushrules) : null;
   }
 
@@ -2732,15 +2732,14 @@ class Client extends MatrixApi {
   /// rule of the push rules: https://matrix.org/docs/spec/client_server/r0.6.0#m-rule-master
   bool get allPushNotificationsMuted {
     final Map<String, Object?>? globalPushRules =
-        _accountData[EventTypes.PushRules]?.content['global']
-                is Map<String, Object?>?
-            ? _accountData[EventTypes.PushRules]?.content['global']
-                as Map<String, Object?>?
-            : null;
+        _accountData[EventTypes.PushRules]
+            ?.content
+            .tryGetMap<String, Object?>('global');
     if (globalPushRules == null) return false;
 
-    if (globalPushRules['override'] is List) {
-      for (final pushRule in globalPushRules['override'] as List) {
+    final globalPushRulesOverride = globalPushRules.tryGetList('override');
+    if (globalPushRulesOverride != null) {
+      for (final pushRule in globalPushRulesOverride) {
         if (pushRule['rule_id'] == '.m.rule.master') {
           return pushRule['enabled'];
         }
@@ -2817,13 +2816,12 @@ class Client extends MatrixApi {
   }
 
   /// A list of mxids of users who are ignored.
-  List<String> get ignoredUsers => (_accountData
-              .containsKey('m.ignored_user_list') &&
-          _accountData['m.ignored_user_list']?.content['ignored_users'] is Map)
-      ? List<String>.from((_accountData['m.ignored_user_list']
-              ?.content['ignored_users'] as Map<String, Object?>)
-          .keys)
-      : [];
+  List<String> get ignoredUsers =>
+      List<String>.from(_accountData['m.ignored_user_list']
+              ?.content
+              .tryGetMap<String, Object?>('ignored_users')
+              ?.keys ??
+          <String>[]);
 
   /// Ignore another user. This will clear the local cached messages to
   /// hide all previous messages from this user.
diff --git a/lib/src/event.dart b/lib/src/event.dart
index 14b563b4..c7e6f3e4 100644
--- a/lib/src/event.dart
+++ b/lib/src/event.dart
@@ -259,9 +259,7 @@ class Event extends MatrixEvent {
 
   String get messageType => type == EventTypes.Sticker
       ? MessageTypes.Sticker
-      : (content['msgtype'] is String
-          ? content['msgtype'] as String
-          : MessageTypes.Text);
+      : (content.tryGet<String>('msgtype') ?? MessageTypes.Text);
 
   void setRedactionEvent(Event redactedBecause) {
     unsigned = {
@@ -303,12 +301,10 @@ class Event extends MatrixEvent {
   }
 
   /// Returns the body of this event if it has a body.
-  String get text => content['body'] is String ? content['body'] as String : '';
+  String get text => content.tryGet<String>('body') ?? '';
 
   /// Returns the formatted boy of this event if it has a formatted body.
-  String get formattedText => content['formatted_body'] is String
-      ? content['formatted_body'] as String
-      : '';
+  String get formattedText => content.tryGet<String>('formatted_body') ?? '';
 
   /// Use this to get the body.
   String get body {
@@ -401,16 +397,11 @@ class Event extends MatrixEvent {
       );
     }
 
-    String transactionId = eventId;
-    if (unsigned?['transaction_id'] is String) {
-      transactionId = unsigned?['transaction_id'] as String;
-    }
-
     // we do not remove the event here. It will automatically be updated
     // in the `sendEvent` method to transition -1 -> 0 -> 1 -> 2
     return await room.sendEvent(
       content,
-      txid: txid ?? transactionId,
+      txid: txid ?? unsigned?.tryGet<String>('transaction_id') ?? eventId,
     );
   }
 
@@ -440,15 +431,19 @@ class Event extends MatrixEvent {
         content['can_request_session'] != true) {
       throw ('Session key not requestable');
     }
-    await room.requestSessionKey(
-        content['session_id'] as String, content['sender_key'] as String);
+
+    final sessionId = content.tryGet<String>('session_id');
+    final senderKey = content.tryGet<String>('sender_key');
+    if (sessionId == null || senderKey == null) {
+      throw ('Unknown session_id or sender_key');
+    }
+    await room.requestSessionKey(sessionId, senderKey);
     return;
   }
 
   /// Gets the info map of file events, or a blank map if none present
-  Map get infoMap => content['info'] is Map
-      ? content['info'] as Map<String, Object?>
-      : <String, Object?>{};
+  Map get infoMap =>
+      content.tryGetMap<String, Object?>('info') ?? <String, Object?>{};
 
   /// Gets the thumbnail info map of file events, or a blank map if nonepresent
   Map get thumbnailInfoMap => infoMap['thumbnail_info'] is Map
@@ -471,10 +466,10 @@ class Event extends MatrixEvent {
   /// Gets the mimetype of the attachment of a file event, or a blank string if not present
   String get attachmentMimetype => infoMap['mimetype'] is String
       ? infoMap['mimetype'].toLowerCase()
-      : (content['file'] is Map &&
-              (content['file'] as Map<String, Object?>)['mimetype'] is String
-          ? (content['file'] as Map<String, Object?>)['mimetype']
-          : '');
+      : (content
+              .tryGetMap<String, Object?>('file')
+              ?.tryGet<String>('mimetype') ??
+          '');
 
   /// Gets the mimetype of the thumbnail of a file event, or a blank string if not present
   String get thumbnailMimetype => thumbnailInfoMap['mimetype'] is String
@@ -487,7 +482,7 @@ class Event extends MatrixEvent {
   /// Gets the underlying mxc url of an attachment of a file event, or null if not present
   Uri? get attachmentMxcUrl {
     final url = isAttachmentEncrypted
-        ? (content['file'] as Map<String, Object?>)['url']
+        ? (content.tryGetMap<String, Object?>('file')?['url'])
         : content['url'];
     return url is String ? Uri.tryParse(url) : null;
   }
@@ -772,22 +767,17 @@ class Event extends MatrixEvent {
     // if we need to strip the reply fallback.
     var htmlMessage = content['format'] != 'org.matrix.custom.html';
     // If we have an edit, we want to operate on the new content
+    final newContent = content.tryGetMap<String, Object?>('m.new_content');
     if (hideEdit &&
         relationshipType == RelationshipTypes.edit &&
-        content.tryGet<Map<String, dynamic>>('m.new_content') != null) {
-      if (plaintextBody &&
-          (content['m.new_content'] as Map<String, Object?>)['format'] ==
-              'org.matrix.custom.html') {
+        newContent != null) {
+      if (plaintextBody && newContent['format'] == 'org.matrix.custom.html') {
         htmlMessage = true;
         body = HtmlToText.convert(
-            (content['m.new_content'] as Map<String, dynamic>)
-                    .tryGet<String>('formatted_body') ??
-                formattedText);
+            newContent.tryGet<String>('formatted_body') ?? formattedText);
       } else {
         htmlMessage = false;
-        body = (content['m.new_content'] as Map<String, dynamic>)
-                .tryGet<String>('body') ??
-            body;
+        body = newContent.tryGet<String>('body') ?? body;
       }
     }
     // Hide reply fallback
@@ -829,33 +819,27 @@ class Event extends MatrixEvent {
 
   /// Get the relationship type of an event. `null` if there is none
   String? get relationshipType {
-    if (content.tryGet<Map<String, dynamic>>('m.relates_to') == null) {
+    final mRelatesTo = content.tryGetMap<String, Object?>('m.relates_to');
+    if (mRelatesTo == null) {
       return null;
     }
-    if ((content['m.relates_to'] as Map<String, Object?>)
-        .containsKey('rel_type')) {
-      if (content
-              .tryGet<Map<String, dynamic>>('m.relates_to')
-              ?.tryGet<String>('rel_type') ==
-          RelationshipTypes.thread) {
-        return RelationshipTypes.thread;
-      }
+    final relType = mRelatesTo.tryGet<String>('rel_type');
+    if (relType == RelationshipTypes.thread) {
+      return RelationshipTypes.thread;
     }
-    if ((content['m.relates_to'] as Map<String, Object?>)
-        .containsKey('m.in_reply_to')) {
+
+    if (mRelatesTo.containsKey('m.in_reply_to')) {
       return RelationshipTypes.reply;
     }
-    return content
-        .tryGet<Map<String, dynamic>>('m.relates_to')
-        ?.tryGet<String>('rel_type');
+    return relType;
   }
 
   /// Get the event ID that this relationship will reference. `null` if there is none
   String? get relationshipEventId {
-    final relatesToMap = content.tryGetMap<String, dynamic>('m.relates_to');
+    final relatesToMap = content.tryGetMap<String, Object?>('m.relates_to');
     return relatesToMap?.tryGet<String>('event_id') ??
         relatesToMap
-            ?.tryGetMap<String, dynamic>('m.in_reply_to')
+            ?.tryGetMap<String, Object?>('m.in_reply_to')
             ?.tryGet<String>('event_id');
   }
 
diff --git a/lib/src/room.dart b/lib/src/room.dart
index a40f7404..c29cad81 100644
--- a/lib/src/room.dart
+++ b/lib/src/room.dart
@@ -267,9 +267,10 @@ class Room {
     }
     if (membership == Membership.leave) {
       final invitation = getState(EventTypes.RoomMember, client.userID!);
-      if (invitation != null && invitation.unsigned?['prev_sender'] != null) {
+      if (invitation != null &&
+          invitation.unsigned?.tryGet<String>('prev_sender') != null) {
         final name = unsafeGetUserFromMemoryOrFallback(
-                invitation.unsigned?['prev_sender'] as String)
+                invitation.unsigned!.tryGet<String>('prev_sender')!)
             .calcDisplayname(i18n: i18n);
         return i18n.wasDirectChatDisplayName(name);
       }
@@ -1748,7 +1749,7 @@ class Room {
       return getState(EventTypes.RoomCreate)?.senderId == userId ? 100 : 0;
     }
     return powerLevelMap
-            .tryGetMap<String, dynamic>('users')
+            .tryGetMap<String, Object?>('users')
             ?.tryGet<int>(userId) ??
         powerLevelMap.tryGet<int>('users_default') ??
         0;
@@ -1803,7 +1804,7 @@ class Room {
     final powerLevelMap = getState(EventTypes.RoomPowerLevels)?.content;
     if (powerLevelMap == null) return 0;
     return powerLevelMap
-            .tryGetMap<String, dynamic>('events')
+            .tryGetMap<String, Object?>('events')
             ?.tryGet<int>(action) ??
         powerLevelMap.tryGet<int>('state_default') ??
         50;
@@ -1834,9 +1835,8 @@ class Room {
     final currentPowerLevelsMap = getState(EventTypes.RoomPowerLevels)?.content;
     if (currentPowerLevelsMap != null) {
       final newPowerLevelMap = currentPowerLevelsMap;
-      final eventsMap = newPowerLevelMap['events'] is Map<String, Object?>
-          ? newPowerLevelMap['events'] as Map<String, Object?>
-          : <String, Object?>{};
+      final eventsMap = newPowerLevelMap.tryGetMap<String, Object?>('events') ??
+          <String, Object?>{};
       eventsMap.addAll({
         EventTypes.GroupCallPrefix: getDefaultPowerLevel(currentPowerLevelsMap),
         EventTypes.GroupCallMemberPrefix:
@@ -1904,7 +1904,7 @@ class Room {
     final powerLevelsMap = getState(EventTypes.RoomPowerLevels)?.content;
     if (powerLevelsMap == null) return 0 <= ownPowerLevel;
     final pl = powerLevelsMap
-            .tryGetMap<String, dynamic>('events')
+            .tryGetMap<String, Object?>('events')
             ?.tryGet<int>(eventType) ??
         powerLevelsMap.tryGet<int>('events_default') ??
         0;
@@ -1916,7 +1916,7 @@ class Room {
     final userLevel = getPowerLevelByUserId(userid);
     final notificationLevel = getState(EventTypes.RoomPowerLevels)
             ?.content
-            .tryGetMap<String, dynamic>('notifications')
+            .tryGetMap<String, Object?>('notifications')
             ?.tryGet<int>(notificationType) ??
         50;
 
diff --git a/lib/src/timeline.dart b/lib/src/timeline.dart
index 5964582b..7ea015bf 100644
--- a/lib/src/timeline.dart
+++ b/lib/src/timeline.dart
@@ -347,16 +347,16 @@ class Timeline {
       if (event.type == EventTypes.Encrypted &&
           event.messageType == MessageTypes.BadEncrypted &&
           event.content['can_request_session'] == true) {
-        try {
+        final sessionId = event.content.tryGet<String>('session_id');
+        final senderKey = event.content.tryGet<String>('sender_key');
+        if (sessionId != null && senderKey != null) {
           room.client.encryption?.keyManager.maybeAutoRequest(
             room.id,
-            event.content['session_id'] as String,
-            event.content['sender_key'] as String,
+            sessionId,
+            senderKey,
             tryOnlineBackup: tryOnlineBackup,
             onlineKeyBackupOnly: onlineKeyBackupOnly,
           );
-        } catch (_) {
-          // dispose
         }
       }
     }
@@ -387,9 +387,9 @@ class Timeline {
     for (i = 0; i < events.length; i++) {
       final searchHaystack = <String>{events[i].eventId};
 
-      final txnid = events[i].unsigned?['transaction_id'];
+      final txnid = events[i].unsigned?.tryGet<String>('transaction_id');
       if (txnid != null) {
-        searchHaystack.add(txnid as String);
+        searchHaystack.add(txnid);
       }
       if (searchNeedle.intersection(searchHaystack).isNotEmpty) {
         break;
@@ -401,11 +401,9 @@ class Timeline {
   void _removeEventFromSet(Set<Event> eventSet, Event event) {
     eventSet.removeWhere((e) =>
         e.matchesEventOrTransactionId(event.eventId) ||
-        (event.unsigned != null &&
+        event.unsigned != null &&
             e.matchesEventOrTransactionId(
-                (event.unsigned?['transaction_id'] is String)
-                    ? (event.unsigned?['transaction_id'] as String)
-                    : null)));
+                event.unsigned?.tryGet<String>('transaction_id')));
   }
 
   void addAggregatedEvent(Event event) {
diff --git a/lib/src/utils/device_keys_list.dart b/lib/src/utils/device_keys_list.dart
index 190a6010..44456a26 100644
--- a/lib/src/utils/device_keys_list.dart
+++ b/lib/src/utils/device_keys_list.dart
@@ -275,7 +275,7 @@ abstract class SignableKey extends MatrixSignableKey {
         var haveValidSignature = false;
         var gotSignatureFromCache = false;
         final fullKeyIdBool = validSignatures
-            ?.tryGetMap<String, dynamic>(otherUserId)
+            ?.tryGetMap<String, Object?>(otherUserId)
             ?.tryGet<bool>(fullKeyId);
         if (fullKeyIdBool == true) {
           haveValidSignature = true;
@@ -426,14 +426,15 @@ class DeviceKeys extends SignableKey {
   late DateTime lastActive;
 
   String? get curve25519Key => keys['curve25519:$deviceId'];
-  String? get deviceDisplayName => unsigned?['device_display_name'] as String;
+  String? get deviceDisplayName =>
+      unsigned?.tryGet<String>('device_display_name');
 
   bool? _validSelfSignature;
   bool get selfSigned =>
       _validSelfSignature ??
       (_validSelfSignature = (deviceId != null &&
               signatures
-                      ?.tryGetMap<String, dynamic>(userId)
+                      ?.tryGetMap<String, Object?>(userId)
                       ?.tryGet<String>('ed25519:$deviceId') ==
                   null
           ? false
diff --git a/lib/src/utils/event_localizations.dart b/lib/src/utils/event_localizations.dart
index 4e754e3b..857418ba 100644
--- a/lib/src/utils/event_localizations.dart
+++ b/lib/src/utils/event_localizations.dart
@@ -204,11 +204,11 @@ abstract class EventLocalizations {
             event.senderFromMemoryOrFallback.calcDisplayname(i18n: i18n)),
     EventTypes.RoomName: (event, i18n, body) => i18n.changedTheChatNameTo(
         event.senderFromMemoryOrFallback.calcDisplayname(i18n: i18n),
-        event.content['name'] as String),
+        event.content.tryGet<String>('name') ?? ''),
     EventTypes.RoomTopic: (event, i18n, body) =>
         i18n.changedTheChatDescriptionTo(
             event.senderFromMemoryOrFallback.calcDisplayname(i18n: i18n),
-            event.content['topic'] as String),
+            event.content.tryGet<String>('topic') ?? ''),
     EventTypes.RoomAvatar: (event, i18n, body) => i18n.changedTheChatAvatar(
         event.senderFromMemoryOrFallback.calcDisplayname(i18n: i18n)),
     EventTypes.GuestAccess: (event, i18n, body) {
@@ -260,7 +260,7 @@ abstract class EventLocalizations {
     EventTypes.Reaction: (event, i18n, body) => i18n.sentReaction(
           event.senderFromMemoryOrFallback.calcDisplayname(i18n: i18n),
           event.content
-                  .tryGetMap<String, dynamic>('m.relates_to')
+                  .tryGetMap<String, Object?>('m.relates_to')
                   ?.tryGet<String>('key') ??
               body,
         ),
diff --git a/lib/src/utils/image_pack_extension.dart b/lib/src/utils/image_pack_extension.dart
index b36453f4..d2db19e3 100644
--- a/lib/src/utils/image_pack_extension.dart
+++ b/lib/src/utils/image_pack_extension.dart
@@ -60,14 +60,14 @@ extension ImagePackRoomExtension on Room {
     addImagePack(client.accountData['im.ponies.user_emotes'], slug: 'user');
     // next we add all the external image packs
     final packRooms = client.accountData['im.ponies.emote_rooms'];
-    if (packRooms != null && packRooms.content['rooms'] is Map) {
-      for (final roomEntry
-          in (packRooms.content['rooms'] as Map<String, Object?>).entries) {
+    final rooms = packRooms?.content.tryGetMap<String, Object?>('rooms');
+    if (packRooms != null && rooms != null) {
+      for (final roomEntry in rooms.entries) {
         final roomId = roomEntry.key;
         final room = client.getRoomById(roomId);
-        if (room != null && roomEntry.value is Map) {
-          for (final stateKeyEntry
-              in (roomEntry.value as Map<String, Object?>).entries) {
+        final roomEntryValue = roomEntry.value;
+        if (room != null && roomEntryValue is Map<String, Object?>) {
+          for (final stateKeyEntry in roomEntryValue.entries) {
             final stateKey = stateKeyEntry.key;
             final fallbackSlug =
                 '${room.getLocalizedDisplayname()}-${stateKey.isNotEmpty ? '$stateKey-' : ''}${room.id}';
diff --git a/lib/src/voip/voip.dart b/lib/src/voip/voip.dart
index dbef3808..9331043e 100644
--- a/lib/src/voip/voip.dart
+++ b/lib/src/voip/voip.dart
@@ -704,18 +704,20 @@ class VoIP {
 
     final groupCallId = event.stateKey;
 
-    final callType = content['m.type'];
+    final callType = content.tryGet<String>('m.type');
 
-    if (callType != GroupCallType.Video && callType != GroupCallType.Voice) {
+    if (callType == null ||
+        callType != GroupCallType.Video && callType != GroupCallType.Voice) {
       Logs().w('Received invalid group call type $callType for room $roomId.');
       return null;
     }
 
-    final callIntent = content['m.intent'];
+    final callIntent = content.tryGet<String>('m.intent');
 
-    if (callIntent != GroupCallIntent.Prompt &&
-        callIntent != GroupCallIntent.Room &&
-        callIntent != GroupCallIntent.Ring) {
+    if (callIntent == null ||
+        callIntent != GroupCallIntent.Prompt &&
+            callIntent != GroupCallIntent.Room &&
+            callIntent != GroupCallIntent.Ring) {
       Logs()
           .w('Received invalid group call intent $callType for room $roomId.');
       return null;
@@ -726,8 +728,8 @@ class VoIP {
       voip: this,
       room: room,
       groupCallId: groupCallId,
-      type: callType as String,
-      intent: callIntent as String,
+      type: callType,
+      intent: callIntent,
     );
 
     groupCalls[groupCallId!] = groupCall;