I even tried just moving my units around to let the AI win but when it got to my last unit and AI tried to kill it - up popped the error message. I recall we had a similar issue with being unable to kill last unit and being stuck in battle screen some time ago so it seems to be an issue - or a variation of it - that we've suffered before. Meanwhile I and others are effectively locked out of game - can't access city, can't do pvp, quests, collect goods fp's etc etc. This is becoming tedious ( not my first choice of a word )