I did not let Shadowheart into the party. My character is a cleric so there was no need for her. When I go to enter the goblin camp She appears on the bridge and there is a cutscene with the artifact. After this point I can no longer save. Loading an earlier save does not fix the problem. If I load an earlier save I can't save again. That's going all the way back to the very first save. Not one of them works. I play on stadia but I saw somebody else supposed the same problem on Reddit today and they are playing on a PC. If I can't save the game is over.
