I had the same problem and get the same error .Make clean install with stable and beta builds but now i have different problem.After finishing a bounty bot waits until the rift closes and open it again but if somehow it leaves (if he dies a lot and cant repair) from the game it wont start a new game.Just hang out on the character screen menu.
Oh one addition ; if the bot dies it revives the corpse but it wont start from the last checkpoint.It just stay dead on the ground.I have to click it manually