⚠️ RimWorld Mod Troubleshooting

Open Player.log at %USERPROFILE%/AppData/LocalLow/Ludeon Studios/RimWorld by Ludeon Studios/Player.log and find the line naming the failing mod. The usual cause is a missing framework — subscribe to Harmony and HugsLib on the Steam Workshop, enable them at the top of the mod list right under Core, and run RimPy's auto-sort.

The mod failed during load, almost always from a missing dependency or an XML error in its defs. Check Player.log for the mod's name, enable every framework it lists (Harmony, HugsLib, JecsTools), then re-enable the mod and reload.

RimWorld and mods each carry a version tag (for example 1.5). Update the mod through the Steam Workshop if one exists, or switch RimWorld back to the version the mod targets using Steam > Properties > Betas. Older abandoned mods may simply not work on the current version.

This is a broken or incomplete XML def in that mod. Unsubscribe and resubscribe on Steam (or re-download the ZIP and re-copy the folder for a manual mod), then enable it again. If it still errors, the mod is likely abandoned for your game version — drop it.

When two mods patch the same def, load order decides the winner. Run RimPy's auto-sort, and check the mod pages for a compatibility patch. If none exists, keep only one of the conflicting mods.

Load time, map loading, and ticks-per-second all get worse as the mod count grows. Disable mods you do not actually use, and consider a performance mod like RocketMan or Performance Fish. The reliable fix is cutting heavy mods and re-adding them in small batches.

The mod requires Royalty, Ideology, Biotech, or Anomaly — its Workshop description says which. Either buy and enable the DLC, or skip the mod. Some DLC-gated mods still start with warnings but lose their DLC-only content.

The save still references defs from the removed mod. Re-enable that mod (or a compatible successor) to get the save loading, remove the mod's items in-game, then disable it again. Back up your Saves folder (Documents/Ludeon Studios/RimWorld by Ludeon Studios/Saves) before changing mod lists mid-colony.

Restart Steam so the Workshop download registers, then relaunch RimWorld and check the Mods menu. Confirm the subscription is for RimWorld specifically. If it still doesn't appear, unsubscribe and resubscribe, or install that mod manually into the Mods folder.

Game updates disable mods flagged for the old version. Re-enable them in the Mods menu, then run RimPy's sort. If you saved a mod list in RimPy, restore that profile to get everything back at once.

Subscribe to the official Harmony mod on the Steam Workshop and place it first in the active list, directly under Core, so it loads before every mod that needs it. RimPy's auto-sort does this automatically; avoid mods that bundle their own conflicting copy of Harmony.

Disable that mod and test — a hard crash usually points at one mod or a mod pair. Enable your list in small batches until the culprit is found, and check Player.log to see which mod was loading last.

If the mod loaded without red errors, its content only spawns in worlds and colonies created after it was enabled — start a new game to get it. If it's a failed-load issue, fix the dependency or XML error first, then start fresh.

Running both copies causes duplicate-def errors and conflicts. Keep one: unsubscribe from the Workshop copy while you test the manual one, or delete the manual folder from the Mods directory, then reload the game.

A yellow triangle means RimWorld suspects the mod is outdated or otherwise problematic for your version. Hover over it for the reason and check for an update. If it loads clean you can ignore it — but treat red errors, which are load failures, as blocking.

That first load recompiles the C# code of new mods (the "Compiling mod code" step) and is always slower; later launches are faster. If every launch is slow, the list is simply too big — trim it or rebuild it in RimPy.

In Steam, right-click RimWorld > Manage > Browse local files, then open the Mods folder inside the game directory. If it is missing, launch the game once to create it. A manual mod must sit as one subfolder containing About/About.xml.

Your save references defs from mods that are no longer active or that changed. Load the save, let the game warn you, and remove the affected items. If the save is broken beyond use, the mod list changed — re-add the missing mod or start a new colony.