They need to fix this. What happens is that often I am in stealth and running behind an enemy and I get in stealth assassination range and press the button when the prompt appears, at this point you no longer have control of your character and what has happened to me many times is that my guy will just run behind the other guy and then just do a regular melee from behind which drains my energy and doesn't kill the guy. They need to fix this because now every time I try to do a stealth assassination im left praying it will actually work. Does anyone else have this issue?

I have also experienced such an issue on the PC version of crysis 2.

I haven't had this problem, but I recommend being as close as possible before trying to melee

You're trying to assassinate a moving player, which often messes up.

Assassinations are primarily for taking guys out who are camping or standing still while firing. It DOES work on moving opponents, but it's less reliable.. If you're running behind them shoot them and stop trying to do an assassination, which will take you out of cloak anyway.

i think it's ok that you cant assasinate a running enemy.
to me it seems normal cuz its logical and realistic xD
imagine: you are running for your enemy (even without nanosuit speed boost), trying to be unnoticed, than grabbing him and breaking his neck xD