Seems like there's case sensitivity issues regarding the GameData/KcalbelohSystem/cache/ directory. Windows is case-insensitive, Linux/*nix is case-sensitive, so capitalization matters in the latter case. Some hardcoded stuff seems to want uppercase "Cache", while the config files request lowercase "cache". The two possible fixes: (lazy way) create a symlink Cache pointing to cache/ or (IMO the proper way) rename the cache/ directory to Cache/ and change all the config files to use the capitalized name. Here's what I used to perform the latter (run in the GameData/KcalbelohSystem/Configs directory):
sed -i 's%/cache/%/Cache/%g' *