i am getting a similar problem also: W/System (11937): Ignoring header X-Firebase-Locale because its value was null. D/EGL_emulation(11937): app_time_stats: avg=334.20ms min=21.00ms max=526.36ms count=3 W/System (11937): Ignoring header X-Firebase-Locale because its value was null. D/FirebaseAuth(11937): Notifying id token listeners about user ( UlNOwuxRTyNG0ubaedHoaTvgI6C2 ). [log] Error during sign-in: type 'List<Object?>' is not a subtype of type 'PigeonUserDetails?' in type cast. i doest log in, however, then it throws this error. On my emulator, i get a popup saying my credentials were incorrect even though they are.