If the mod has new system nebulae pics, it is FQM Deluxe (2.01).
Load existing races, as in "Add new empire" or "Load Empire"? If the latter, there might be an empty Empires folder in the FQM folder that is causing a problem.
Also, because there is no FQM\Pictures\Races folder, SE4 will look in the default Pictures\Races folder. That does not cause any problems (unless you have no races in your default races folder, which would have required you do have deleted them or renamed the folder

).