I have the same problem! My Poweramp activation is still not working. I tried everything...
The problem: "Überprüfung des Kaufs fehlgeschlagen, dieses E-mail.Konto ist auf dem Gerät nicht registriert! - (yahoo email account not registered)
Here are my facts:
- running on Samsung S5 with Android 6.0.1
- Yahoo-Mail 22.214.171.1248887 - i can check my mails on the phone - Yahoo mail is registered in accounts
- i downloaded the akp from website (Poweramp-2.0.10-build-588-uni.apk)
- i purchased the unlock-code per paypal, i am not able to activate it with my yahoo-emailadress and Order ID
- I tried to install older versions of YahooMail (V4, V3 and V2), but they all are not running on my system... they are "hanging" or got no connection to yahoo servers.
What can i do?