today i remember why this window pop ups.
i started avd manager, then sdk and avd manager opens and booth show nothing because array index out of bounds.
i like to see installed avds to start the emulator from there.
now i must open the android studio and start the emulator from there. (i have also 2 real devices but sometimes a emulator is functional)
last week my emulator was listed in b4a avd manager.
i think some updates make it incompatible with b4a.