Double tapping Left Ctrl (lower/raise weapon) and using the stance modifier Left Ctrl + W/S can result in stuck animations such as either automaticly walking without any way to stop it or being stuck and no way to move again.
I think this can happen if you use the modified stance button while the weapon is lowered.
Only way to snap out of this is to go back out of the current game.
Double tap Left Ctrl to lower weapon, use the stance modifier, use movement keys. It is some combination that will lock your character into either automaticlly walking without any way to stop him or he will be stopped without any way to move him again.
I will try different combos and try to find the correct one (if it exists) and post it here. Ive seen others that have gotten stuck in an automatic walk mode, and i think i now know whats causing it.
Seems to be while walking and double tap ctrl to lower weapon will have you walk automatically and sometimes you can stop it by pressing V or switch weapon.