I have this same problem with my Moto G. If I'm on a plane, or just the other day, on a ferry and out of wifi range, I will suddenly get a failed verification notice and Poweramp shuts down. I looked in Poweramp settings and it showed the purchase as Verified. I also sent an email to Poweramp about this and got no reply. This is really annoying as I like to listen to music on planes and traveling. If there isn't a fix to this I will have to find another music app. Any recommendations? I also would like my money back!!