Ok, so I took a look at this level, that Conrad sent to me.
The issue here is that the fire2.jpg is faulty, it's probably saved with some compression not compatible with Q3, if you save it as a tga or a regular jpg, it works. This gave the error "Requested feature was omitted at compile time" and forced Q3 to quit while loading the level.
You should also know, that the level has a leak in it, there's a gap in the skybox.