lib/structs.dart

@@ -143,6 +143,6 @@ class AttachmentResponse {
   AttachmentResponse({required this.name, required this.data});
 
   factory AttachmentResponse.fromJson(Map<String, dynamic> json) {
-    return AttachmentResponse(name: json["name"], data: json["data"],);
+    return AttachmentResponse(name: json["name"], data: Uint8List.fromList(List<int>.from(json["data"])));
   }
 }