GMod crashes at spawning

My problem is that I booted up GMod to try out a new map my friend made. Right as it made the weapons get sound, it keeps crashing. And that’s on all maps, too: the only map I managed to spawn on was Flatgrass, and even then, it crashed shortly thereafter, after just a few steps. Everything worked fine last week.

Do anyone have any clue how come this happen? Did the L4D or TF2 recent updates break Garry’s Mod or am I alone? Most importantly, do anyone know how to fix it?

Thanks in advance.

Always worth posting your computer specs. Try unmounting L4D.

I don’t own L4D nor L4D2.

Also, computer specs:

Intel Core2Duo 2.4GHz
2GB RAM in a single slot
PNY Technologies NVidia GeForce 9500GT
Realtek onboard sound device
Windows XP Pro SP3 (Although it is to be noted I use the SharpEnviro shell and run a dual-screen configuration)

And as previously said, GMod was working fine the week prior.

What addons do you have installed?

Adv. dupe, Ball swep, BF2 buggy, Custom crosshairs, Fairy, Faphack, GBombs (+icons), GB Radial menu, Haxgun, helicopter vehicle, PAC2, PHX, Wire, SMAC sinewave gun, smart constraint, smartsnap, Smart Weld, Stacker, Super Parent Multi, Weight stool, Wenlis’ stools, and UWSVN.

Mounted games: EP1&2, Lost Coast, Portal and TF2.

Oh and if it can help: the menu and everything works fine. It specifically crashes when trying to load a map.

Re-install Garry’s Mod.

Are you certain there is no less drastic measures to be taken?

It would likely solve any (or all) problems. You can backup your Addons/Maps.

Well, it did work. Thank you guys.