help my instruments don't play back any more
If you have changed ufxloops storage either from internal storage to sdcard or vice versa and you have removed that sdcard.
Or if you have selected an sdcard you just inserted as default phone read and write storage.
You just need to correct your deed from either one of the two actions listed above.
Does this answer help your case?
Or you could be running out of memory on wherever you have stored it on.
The best way to take care of that is first, if you have any songs you recorded that you want to keep, retreive them from your phone , under the live recordings section of the ufx folder in the data folder of the Android folder or your settings folder.
Also ,make sure you registered with UFX Loops in order to retrieve your instruments back that you already paid coins for , as you are going to have to get them again after this , and re record your tracks.
Now you can either clear the cache in the app in the apps folder of your settings menu, and try it after that. Log in to UFX loops.
Or you can uninstall and then reinstall the app.
Both of those ways will give you back your sound. make sure to have enough space available where you have it stored ,so that it doesn't do that again.