Entity Skins Vanish

[MsHannerBananer]

I have a grandfather clock in one of my maps.

It used to show up in the map, but all of sudden it doesn't anymore. The entity is still there, because when I walk into it, there's something invisible there preventing me from moving forward. So the entity works otherwise, but it's just invisible. Is there a way to fix this?

I haven't tampered with the files in any way. I copy and past custom models to custom folders for use, but otherwise the files are unchanged.