I'm not sure what it's caused by, although I have glimpsed some people in chat talking about it so someone probably knows, anyway here's a screencap that I have of it (probably?):
Has something to do with the bump map layer, afaik. There's a ground texture that does the same thing.
Has something to do with the bump map layer, afaik. There's a ground texture that does the same thing.
The checkerboard is the source error texture, it is used when the correct texture failed to load, usually because it doesn't exist.
Basically check the material for which textures it uses and verify that those exist.
Also, verify your cache in steam to ensure that no files have gone corrupt.
(No, not pink and black. This has nothing to do with missing textures or cubemaps)
Are you sure this is a stock texture and one designed for TF2? I can't tell from that screenshot what it's actually supposed to be.