Ok, looking at the tickets you submitted on this, I can confirm this is a known issue. It's a very stubborn one we have been trying to figure out, but there is nothing we can do to actually fix it right now. It seems to happen more when using some attacks (such as sniper shot), but that is inconsistent. Something similar happens in Champions (getting stuck in a charge animation, can't move), but the exact trigger for that has remained elusive as well.
I'm sorry the responses you got were not as helpful as they might have been. Unfortunately, though, the only remedy for this happening is to map transfer or log out and back in.
Just happened to me as well. It seemed like it might've been caused by an enemy dying as I tried using a special attack in him. Got stuck repeating the start of that animation.
I've also had this happen to me. It does it on random ground missions and i have to exit the mission or log out and log back to fix it. Just being killed and respawning won't fix it. It seems to happen if I am firing weapons and using abilities at the same time or very close together. I don't know the exact key stroke/mouse click combo to do it, but if fire my ground weapon using the primary (or secondary) effect and click on an ability (create phaser turret etc) I will get stuck couching, then raising my weapon and the end of the weapon will glow like its going to fire, (but never does) and then it loops back to the couch, it will go through this loop forever. I can still use abilities and command BO's (and be killed), but no way to end it without leaving the mission. The most recent time it happened to me was on infected when fighting the queen, but its happened on the Big Dig and some random ground missions. Very frustrating to be disabled when I'm needed most. (was able to help kill the queen by creating phaser turrets, mortars, med and shield gens, but couldn't shoot her). I'll see if I can figure out what can cause it, but thankfully, its very infrequent (one time in 8 hours play), but highly frustrating to have to play a mission over again (or back to the last major point) when it happens. Hope that helps some.
Do you have any details I can go on to investigate? The mission name, where you were, a bug report number, are all important. Are you having this with just one mission, or are you describing something that's happening on multiple missions?
I have had the exact same problems more times than I can count. Here's a ticket number. 907,912.
I have had similar issues with missions form getting stuck in random boxes, and even a wierd spawning issue where i spawned INSIDE a rock, fell to the bottom and got given the red box to beam out because i "left the area" even crew members are getting spawned inside objects on some maps, though all of teghse instances have involved doing cluster missions, typically ground scan missions where there are enemies to fight, and occasionally inside the asterid base scan missions. Not too sure, but i haven't seen it happen to me anywhere else. Tried re-installing the game to see if it would fix it, possibly a corrupt mapping file or something, but no dice.