There's a bug in 1.8.3 where the mod will fail to load on Linux due to path being wrong
filename = "RealisticFusionPower/compatibility-patches/booktorio/gs-process.png"
The folder it refers to is "Booktorio" with capital B, while the path is "booktorio". On linux, path is case-sensitive.
Proper path should be
filename = "RealisticFusionPower/compatibility-patches/Booktorio/gs-process.png"