Garrys mod crashing whenever I click the fire button

I don’t know if this will actual get noticed, but I’m obviously having troubles with Gmod. First of all, I can run it fine and load up a map, but whenever I click the right mouse button to use my gravity gun. Gmod instantly crashes. So please to anyone who reads this give any info you possible can give because I’ve had this game since 2009, and I miss it dearly.

System Specs? (If you can’t find them use Speccy (www.piriform.com/speccy))

Addons Installed? (If any)