Use this fix only if you have problems with the animated high-res nebula textures from better planets and backgrounds.
Mostly mac users have reported that the high res nebula textures from better planets and backgrounds are causing problems and artifacts...
So if you experience such problems use one of the .ftl files provided here. One comes with the original texture size, the other with twice the original texture size.
If you don't want to fix the problem with low-res textures you also can disable the animated textures in the FTL options menu.
For questions check the forum thread at Ftlgame.com