Bad state: Future already completed in Flutter

Question

I'm getting this error with any flutter command on Big Sur:

Bad state: Future already completed
#0      _AsyncCompleter.complete (dart:async/future_impl.dart:43:31)
#1      _NativeSocket.startConnect.<anonymous closure>.connectNext.<anonymous closure> (dart:io-patch/socket_patch.dart:682:23)
#2      _NativeSocket.issueWriteEvent.issue (dart:io-patch/socket_patch.dart:1102:14)
#3      _NativeSocket.issueWriteEvent (dart:io-patch/socket_patch.dart:1109:12)
#4      _NativeSocket.multiplex (dart:io-patch/socket_patch.dart:1130:11)
#5      _RawReceivePortImpl._handleMessage (dart:isolate-patch/isolate_patch.dart:168:12)
Error: Unable to 'pub upgrade' flutter tool. Retrying in five seconds... (6 tries left)

the only thing I changed was install AdGuard but I completely remove it. Now I can't get rid of this error after trying different methods to fix it.

I also have Bitdefender but don't think this is related because I had this install since very beginning (also this is a requirement from my company and I cannot modify anything here)

Answer 1

Approach 1:

Try using flutter config --no-analytics . It should be working fine.

Refrence .

Approach 2:

If you are using third party antivirus programs try to uninstall and reinstall the program or deactivate the option "Scan secure connection" on Web Shield (Core Shields)