Just FYI, sometimes when you perform a stealth takedown (on PC), you'll sometimes be unable to shoot or melee or do anything with your guns. I'll unplug my mouse and plug it back in but it doesn't work. However, if I perform another stealth takedown during this glitch, it'll make it so that I can shoot again. Keep in mind you're still able to change weapons, move and jump during this glitch, but nothing offensive.