I just had the same problem after responding to an update notification from Google Playstore for my full version purchased copy. Here is how I solved it. 1. Uninstall Poweramp (don't uninstall the unlocker) 2. In /sdcard/android/data there is a directory called _com.maxmpz.audioplayer. Delete this last directory and its contents. 3. Install Poweramp. The error was gone. 4. Run the unlocker again. Good luck.