Originally posted by Evil Rayman
Did you construct the background yourself?
All BG ExGFX require you to do that.
Not all. If it came with an mwl level file, which is now mandatory, you can simply insert that via File → Open Level From File, insert the MAP16 page, and change the BG slot used in GFX Bypass. Be careful when saving though, it will overwrite a level you don't want it to if you don't do File → Save instead of the save button.