I'd like to add my voice to the frustration of this licence check error.
It caused me a lot of stress last night. I use an old simm less phone as a music player for an exercise class and this error appeared for the first time. To make matters worse I couldn't use the playlist I set up on a different music player app. Fortunately I had a backup.
Connecting to a WiFi connection did not help. Neither did uninstalling and reinstalling the unlocker. I found that removing the widget did address the issue.
It is really annoying when people who do the right thing (paying for software) are penalised because of an over zealous licencing system.
Nb I like Poweramp and have purchased it twice (under 2 different Google accounts).