the only way produngeon is working atm is if you set prestige at lvl 4, not 6. I've managed to do a2 hours 45 minutes without any errors after testing it, (its still running). The catch is you get less xp but you get some, and you can afk the whole time.
On the other hand, you could use Idungeon Lite, wich allows you to avrage a v nice xp an hour, the catch is you will have to start the boot after every 4th floor done.
Hope this helps.