Mod conflicts

Fabric Loader Localization.format NumberFormatException on Mod Conflict

What the log looks like

can't parse argument number: \d+\s+[\s\S]{0,600}?net\.fabricmc\.loader\.impl\.util\.Localization\.format
net\.fabricmc\.loader\.impl\.util\.Localization\.format[\s\S]{0,1500}?NumberFormatException: For input string:

How to fix it

  1. Open your instance's logs/latest.log file and find the 'Mod resolution failed' section located directly above 'Uncaught exception in thread "main"'.
  2. Check the 'Reason:' line to identify the real conflict: 'NEG_HARD_DEP' means one mod explicitly breaks another (for example, Sodium/Iris conflicting with OptiFabric), while 'HARD_DEP' means a mod requires a different Minecraft or dependency version.
  3. Remove one of the conflicting mods or update the incompatible mod named in the 'Reason:' line to match your exact Minecraft version.
  4. Update Fabric Loader in your launcher profile to the newest release so future mod dependency errors open the normal diagnostic window instead of crashing on localized text.
LoadersFabric
SeverityStops the game
CategoryMod conflicts

Check your own log

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