Do you really want to fix the DEV ERROR 615 ? For this, you can restart your device or wait for the server issue to be fixed. This sort of game error can also be rectified by restarting the device or disabling third-party apps. Apart from this, players can ask forquick supportfrom the technical team. Through this, you can get solutions of all the queries of game issues.
https://www.gameerrors.com/errors/dev-error-615/