the e1.x.x are early access updates
just had this error the other day, for me it was a bad troop id in the party template xml but it shoudl happen at the start in that case.
not sure the game has any CM, more like some devs are active on the forum
afaik the workshop doesn't work when offline no matter the game, so anything you download from it disapears as long as you are offline
man this so much, castles shouldn't be towns with all the drawbacks and none of the usefulness
have you given it the proper bone attachment point ?
on the 1.2.7 patch notes :
no longer true about the 20% tho