Garry's Mod problem

Disconnect: Kicked by Console : “Mismatch: includes\util.lua”.

What does this mean? Ive Removed all my addons and stuff i got and still has this problem. I have Windows vista if that affects something and i really need help with this scince i’ve had it for months now :confused:

It keeps me from playing on my favourite server Please help

I have Windows Vista Ultimate and i don’t get this problem… try reinstalling GMod then try Steam