Android emulator: unfortunately the process android phone has stopped

After starting an Android virtual device in the emulator the error the following error started appearing in the emulated environment:

unfortunately the process android phone has stopped

The most likely cause was that it was not properly shut down in the previous developing session.The error continued even after repeatedly turning it off and on and appeared in other virtual devices also.After a lot of searching without finding anything helpful, and since there was nothing of value stored in the virtual device I clicked the wipe user data checkbox when I started it. Unexpectedly this fixed the problem and the virtual device started normally.The lesson learned from this experience is that Android virtual devices should always be shut down properly.Also an alternative android emulator is needed in case the problem can't be fixed next time it happens.