found something on steampowered, tell me if it works.
Bug Title: Crosshair is missing. Weapons/Models have weird decals or they show in wireframe.
Bug Description: You can't seem to find your crosshair, you've changed settings in options, but still it won't come back. Your weapons/models don't have their usual look, but rather you see a wireframe or some artifact (black boxes) when you fire your weapon.
Fix 1: Type "cl_crosshair 1" in console. (Only for crosshair bug)
Fix 2: If the first method didn't work, then the only commonality I've seen people report; is that they have previously (prior to the update) have installed a custom crosshair/skin. As far as I can tell you, removing the files associated with it has restored their mods to original models and skins. Now I don't know much about custom skinning, and modeling. But you might need to rebuild/redo them. Or simply re-install them. Also, I'm aware that there is a script file used for the models/skins, for the new engine the specs and format might have changed so you can't use it. The only method I can think of that can help you, is to use a tutorial/guide on installing/creating models and skins for games with similar engines (eg. TF2, DOD:S).