I once accidentally ruined my save while using a mod for version 0.15 instead of 0.18. I just couldn't resist giving it a try! However, the good news is that all I had to do to fix it was to remove the incorrect mod and use the "/fixmapping applyall" command. I didn't have a backup at that time, but I've learned the importance of making backups, especially when you're adding or removing mods. The vanilla game runs incredibly smoothly, and I have to say, for an early access game, it's truly awesome.