Visual error?

Uhhhh What is this ?

http://cloud-2.steampowered.com/ugc/473173565675872496/F266CCE2B5D5561C90F4531B9FD5D0ED2433C327/

and… how do i fix it ? i dont know when it started happening but it’s weird first i thought it was my server but i went in another server and singleplayer and its still all ef’ed up… anyone uhh know how to fix this ?

[editline]9th December 2013[/editline]

Uhh, I found out how to fix it but i still don’t know how it happened…

If you have this problem to all i did was clear my cache folder… idk if that would fix it for everyone but it worked for me.