If you have encountered the above error message when you tried to open your Android Application Project on the Emulator you have then this is because you have may have modified the Configuration settings of the emulator and you have Snapshot option selected.
Why did you get this error ?
You must have previously created an Emulator device with Snapshot option selected. If you select Snapshot option and run it for the first time, the system creates of copy of the OS that is loaded on the RAM to disk, something like Hibernation. Now the next time you load the Emulator its been loaded from this Snapshot, hence the device gets loaded faster compared to a device created by not selecting the Snapshot option.
So now if you change the configuration of this device, this will cause the above error, so any change you make to the AVD with Snapshot be it RAM, Heap, target API, CPU, Skin, Camera etc.
How to make it working :
You need to get back to the previous configuration that you had and which worked! in order to fix this issue.
If you want the configuration changes you made to stay then you must uncheck "Snapshot" option.
If noting works for you!! Well then you have to delete the Emulator and recreate it once again.