Unless I got something fundamentally wrong - please don't hit me if so
You should state that the Donate Version requires you to have a Google Services installed and a Account signed in.
For everybody using "blank" Android versions - Android without any google stuff like AOSP or Cyanogenmod - this is nothing for you! You will end up with a limited version of FPse even if you donate.
I guess this is just to overcome the "local copyright mafia" in several countries banning this software from the Play Store.
Unfortually I appearantly have to find another Emulator, although this worked so well.