Cod MW3 problem stock at taking out enemy…

hi guys… i’ve been playing for few hours already but im having problem at this mission where i have to destroy the tanks by using the javelin…
i can still shoot with the weapons i currently have, but it seems that i cannot move.. not even a single step…. what seems to be the problem??
please help me out guys!
thank you!
Answer #1
restart from your last checkpoint
Answer #2
this kind of problem maximum in Crack game. dnt worry about that. restart the level or last check point.