Yes, looks like an error compiling the bsp. If you want to continue using this editor, you might try making that surface (and maybe all the stairs) a single func_static, so that it isn't involved in the world geometry.
Would have to agree with motorstep, best to use dark radiant or even doom radiant until they figure this out. Also, try compiling with stock doom 3. Let us know if you figure this issue out.
Would have to agree with motorstep, best to use dark radiant or even doom radiant until they figure this out. Also, try compiling with stock doom 3. Let us know if you figure this issue out.