Alright, So I've tried every possible recommended pre-made configuration for Prusaslicer I can find, an I just keep getting the same error message.
So, deciding to throw that out of the window, I just decided to create a new directory, so that Prusa can stop saving the gcode to where ever it feels like it.
with the new directory of /home/username/.local/share/RepetierHost/composition.gcode, I'm now getting a different error. So some progress has been made.
Thankfully, it's not a completely random error, as I'm just getting a Permission Denied message, telling me that RepetierHost doesn't have access to the new folder.
Is there anything you recommend me to do from this stage? I think I can fix it myself, but I'm not 100% confident that RepetierHost would survive.