I was getting several related errors in update 1.1 but the latest update seems to have fixed them so far?

What would stop end turn working for me would be a unit/s trying to walk but just slipping on the spot. Saving and reloading fixed it every time.

Often my auto end turn would not work when it should, accompanied with an erratic auto select unit function that would not select all available units automatically. I always considered this just to be part of the game when one day i decided to redo all my caravan routes. While i was in the process of deleting all the old caravans, i found an old caravan that had not deployed as instructed. I deleted it and suddenly auto end turn and auto unit select started working properly!

So if nothing else works, try deleting all your caravans and see what happens?