Problem Connecting Sometimes

[transilvanian]

Sometimes when I try to connect to the gungame server it comes up with an error saying:

"Server is enforcing consistency for this file: models\weapons\w_rif_m4a1_silencer.mdl"

and then it doesnt let me connect to the server.  I have a skin for my m4, but i dont know if that would be the problem or not? and if that is the problem how do i get a skin back to the original?

Thanks

Cannot access offset of type string on string