After updating to Catalina 10.15.4 beta with Xcode 13.4 beta, which also updated Simulator to 13.4 (921.4).
The application compiles and runs correctly on a physical
Xcode 11.4 changed the way frameworks are linked and embedded, and you may experience issues switching between iOS devices and simulators. Flutter v1.15.3 and later will automatically migrate your Xcode project.
To get unstuck, follow the instructions below;
rm -rf ios/Flutter/App.framework
Official recommended Steps to migrate manually
Change the Runner target build settings Build Phases > Thin Binary script as follows:
/bin/sh "$FLUTTER_ROOT/packages/flutter_tools/bin/xcode_backend.sh" embed
/bin/sh "$FLUTTER_ROOT/packages/flutter_tools/bin/xcode_backend.sh" thin
In the Runner target Build Settings > Other Linker Flags
(OTHER_LDFLAGS) add $(inherited) -framework Flutter
Hope it helps!