As a fellow tux user, I'll cut it down to the point.
You won't be able to load into Dvergheim running the game natively, your only hope if you need to go there/pass through there (which is not necessary unless you're a dwarf) is to use Proton
The problem is related with some texture meshes having names longer then 64 characters and the only way to fix it would be to adjust the files on the server side, which is sadly an Herculean task.