Deus Ex Human Revolution: I can't upgrade my combat rifle with the target-seeking system. Help?

I'm positive I haven't used it yet. And I'm fairly certain the upgrade can be used on the combat rifle... Right?



=/ I'm trying to go for the gun nut achievement. I know the tranq rifle is the easiest to upgrade, but it's one of my least favorite weapons.



Any advice, help would be very appreciated.Deus Ex Human Revolution: I can't upgrade my combat rifle with the target-seeking system. Help?
The Target Seeking System should work for both the Combat Rifle and the Machine Pistol. There is also the Heat Targeting System which only works with the Rocket Launcher. Perhaps you are experiencing a glitch, this is a really new game.Deus Ex Human Revolution: I can't upgrade my combat rifle with the target-seeking system. Help?
isnt target seeking for missle only cant rember off hand witch one that is



also it may be that you have a conflicting mod already installed

look for a new rifle drop current one and see if it installes on that new one if it does then you know it is the current gun and some mod fault



or just another bug