So you can't change your GMod background anymore?

Whenever I try to change my background I still get that ugly default background.I put the files in the right place,I follow the steps and you know what,I still get the ugly background.Am I the only one or is there something I’m doing wrong?I mean I was able to change my background months ago but now I can’t.

happened to me after the update,I think you should take out all the addons and stuff you manually put in there,delete the Garrysmod folder,verify and reinstall it.