Garry's Mod crashes at startup,cant play

[silentrock]

I downloaded Gmod and DoD:Source with UNdead patch (works awsome) an i tried to start Gmod but it crashes with soemthing about hl2.exe
any help this is urgent.thanks

 

[Fallen101]

try
-dxlevel 80

 

[silentrock]

i tried it,and doesnt works,but thanks anyway