Cannot connect to ROS

[Anirudh181001]

Hi, I am able to build and compile the app successfully. However, when I refresh the connection by pressing the refresh button, I am getting this error:
[ERROR:flutter/lib/ui/ui_dart_state.cc(198)] Unhandled Exception: Bad state: No element
#0 Iterable.first (dart:core/iterable.dart:624:7)
#1 RosSubscriber.establishTCPROSConnection. (package:ros_nodes/src/ros_subscriber.dart:124:12)
#2 _rootRunUnary (dart:async/zone.dart:1434:47)
#3 _CustomZone.runUnary (dart:async/zone.dart:1335:19)
#4 _CustomZone.runUnaryGuarded (dart:async/zone.dart:1244:7)
#5 _BufferingStreamSubscription._sendData (dart:async/stream_impl.dart:341:11)
#6 _BufferingStreamSubscription._add (dart:async/stream_impl.dart:271:7)
#7 _ForwardingStreamSubscription._add (dart:async/stream_pipe.dart:123:11)
#8 _TakeStream._handleData (dart:async/stream_pipe.dart:305:12)
#9 _ForwardingStreamSubscription._handleData (dart:async/stream_pipe.dart:153:13)
#10 _rootRunUnary (dart:async/zone.dart:1434:47)
#11 _CustomZone.runUnary (dart:async/zone.dart:1335:19)
#12 _CustomZone.runUnaryGuarded (dart:async/zone.dart:1244:7)
#13 _BufferingStreamSubscription._sendData (dart:async/stream_impl.dart:341:11)
#14 _BufferingStreamSubscription._add (dart:async/stream_impl.dart:271:7)
#15 _SyncBroadcastStreamController._sendData. (dart:async/broadcast_stream_controller.dart:385:20)
#16 _BroadcastStreamController._forEachListener (dart:async/broadcast_stream_controller.dart:322:15)
#17 _SyncBroadcastStreamController._sendData (dart:async/broadcast_stream_controller.dart:384:5)
#18 _BroadcastStreamController.add (dart:async/broadcast_stream_controller.dart:244:5)
#19 _AsBroadcastStreamController.add (dart:async/broadcast_stream_controller.dart:474:11)
#20 _rootRunUnary (dart:async/zone.dart:1434:47)
#21 _CustomZone.runUnary (dart:async/zone.dart:1335:19)
#22 _CustomZone.runUnaryGuarded (dart:async/zone.dart:1244:7)
#23 _BufferingStreamSubscription._sendData (dart:async/stream_impl.dart:341:11)
#24 _BufferingStreamSubscription._add (dart:async/stream_impl.dart:271:7)
#25 _SyncStreamControllerDispatch._sendData (dart:async/stream_controller.dart:774:19)
#26 _StreamController._add (dart:async/stream_controller.dart:648:7)
#27 _StreamController.add (dart:async/stream_controller.dart:596:5)
#28 _Socket._onData (dart:io-patch/socket_patch.dart:2314:41)
#29 _rootRunUnary (dart:async/zone.dart:1442:13)
#30 _CustomZone.runUnary (dart:async/zone.dart:1335:19)
#31 _CustomZone.runUnaryGuarded (dart:async/zone.dart:1244:7)
#32 _BufferingStreamSubscription._sendData (dart:async/stream_impl.dart:341:11)
#33 _BufferingStreamSubscription._add (dart:async/stream_impl.dart:271:7)
#34 _SyncStreamControllerDispatch._sendData (dart:async/stream_controller.dart:774:19)
#35 _StreamController._add (dart:async/stream_controller.dart:648:7)
#36 _StreamController.add (dart:async/stream_controller.dart:596:5)
#37 new _RawSocket. (dart:io-patch/socket_patch.dart:1839:33)
#38 _NativeSocket.issueReadEvent.issue (dart:io-patch/socket_patch.dart:1322:14)
#39 _microtaskLoop (dart:async/schedule_microtask.dart:40:21)
#40 _startMicrotaskLoop (dart:async/schedule_microtask.dart:49:5)

I am really unable to understand why this is happening, and am not able to fix it. Any help would be greatly appreciated! Thanks a lot!