Plutonium

This worked for me on MW3 but I suggest still trying if the problem is on a different game, it might work for you. The "solution" I found by accident is you go into a lobby just like normal but once the match is close to ending open your console, put in your command and try closing the console. You then won't be able to walk, don't worry just stay there and wait for a new match to start, once the new match starts your console should automatically close and you should be able to move freely. Hopefully this helps and have fun gaming .