RimWorld Mods

Mid-saver Saver Mod

Author of the Mid-saver Saver Mod: Owlchemist

“Don’t add or remove mods mid-save”. This is often the advise passed around within the RimWorld modding community. But what fun is that? These problems can be fixed with time and effort, and this utility mod’s goal is to find those solutions.

Mid-saver Saver Mod features

Current list of fixes
Related to adding mods…
  • Hash collisions: This silent killer won’t produce any errors but you’ll notice problems such as stone cliffs and chunks having just disappeared, or deep drills mining up nonsense items. This patch fixes this by temporarily disabling lossy map compression.
  • Retroactive mineables: If a mod added new mineables (like metal ore), this patch can retroactively add them to existing maps.
  • Remap body parts: If a mod adds new body parts or prosthetic augments, this could scramble the save data, causing limbs and injuries to show up on the wrong body parts. This fix will record the before and after and remap the body parts accordingly.
Related to removing mods…
  • Faction removal: Removing factions can corrupt the faction data of world objects. This fix will prune the object registry of any such cases, such as broken faction settlements.
  • Corrupt areas or sectors: If you get the “grey screen of death” on loading your save, your areas or sections may be missing. This fix will regenerate them.
  • Corrupt weather: Removing a mod that added custom weather may also cause the “grey screen of death”. This fix will reset the weather manager.
  • Corrupt ideologies: If you view your ideologies screen and get bombarded by UI errors, you may have a corrupt precept. This fix will remove them from ideologies across all factions.
  • Missing stuff material: If you remove a mod that added materials (metals, stones, etc), and things were made out of those materials, this fix will handle their fallback.


Q. I got a ton of red errors after removing a mod, but I had this installed. Is it not working?
A. Yes, you’ll get errors, that’s perfectly normal. The point of this mod is only to address the fatal errors that would prevent you from doing anything. The remaining errors are just pointing out that it can’t find removed content, which is fine. Save your game, and then reload that save, and they should clear up (you may have to do this 2 times sometimes).

Q. I read the above but I’m still getting serious errors.
A. You either:

  1. Found an issue this mod has not addressed yet. Give me the details and I’ll try to find the cure.
  2. Forgot to actually enable the fixes in the mod options.
  3. The errors are unrelated to mid-save complications, and would have happened even for a fresh save in a new colony, and it’s just the regular mod problem you’ll need to troubleshoot.

Q. Any risks I should know about?
A. Due to the chaotic nature of errors, there may be unknown unknowns. By ripping out mods mid-save, it is technically plausible there could be hidden problems that do not reveal themselves through red errors. These sleeper-bugs, if they exist, will need to be worked out as they’re reported upon.

Why I made this

As a mod author myself, I dislike that people may feel discouraged from subscribing to a mod out of fear that they won’t be able to remove it, or that adding it mid-save could cause issues. If I had it my way, we would be able to add or remove anything, anytime. In theory, these errors can be fixed, someone just needs to step up and do something about it.


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