That is a pretty weird exception. It happens in ui_dart_state.cc according to that stack trace. Can you try debug to the last mentioned line in get_it_implementation and check which variables are null ...

: ref = null, gft = null, spec = null; /// Reference a generic function type. /// Currently maps to [CoreTypes.function] const BridgeTypeRef. genericFunction (this.gft) : typeArgs = const [], ref = ...