Gmod 13 Crashes on Startup

Gmod has always worked fine for me up until 13 but it always crashes right after about 10 seconds saying something about materialsystem error loading

would love some jolly good help

[editline]26th November 2012[/editline]

Error (1) loading VMaterialSystem080 from materialsystem

thats it word for word. no my computer is working fine and is not shitty

Bumping, i got the same problem, freshly updated.