Well if it is having a hiccup on 'revertableobject', I would assume it is getting upset about the format of a rollback. Not really sure what exactly as I am not really the best at reading these, but in the meantime try the following to get you started:
- Close the game and complete a 'verify integrity of game cache' before relaunching it. From here go back into your save and try completing the turn again. - Complete the rollback and then create a new save file. Return to the main menu and then load the save again before trying to complete the turn.
If we can get vaendryl to appear out of the ether we get a proper evaluation.
Be warned, elements of this post may have been influenced by my 'West Country Logic'.