I'm developing an android app using flutter which uses Firebase cloud messaging. Everything was working fine and it was receiving cloud messages but recently nothing happens when the device receives a cloud message no matter the app is in foreground or background or terminated. The only thing that is logged into console is:
E/FlutterFcmService: Fatal: failed to find callback
which from what I know it belongs to the fact that I haven't handled background messages and despite this I should be able to receive the message. how can I realize what is the cause of this problem? a log file or something?
PS: I've tested on real devices with Android version 21 and 29 and the results are the same.
PS: I've done
flutter pub upgrade
flutter pub get
flutter clean
and removed the app entirely then installed it again.
PS: I've sent the message using Firebase console and the project backend. both include 'notification' field inside the message.
Thanks in advance