Undefined symbols for architecture i386: _FlutterMethodNotImplemented
This error is related to Undefined symbols for architecture i386
This worked for me - for the target that reports warnings, change the "Valid Architecture" setting to:
$(VALID_ARCHS)x86_64
P.S In case this doesn't help, go to Build Settings and search for "No Common Blocks" and set it to "No". Build and Run.