Mod conflicts

JEI NullPointerException from Null Recipe ItemStacks or Smelting Recipes

What the log looks like

Caused by: java\.lang\.NullPointerException\s+at net\.minecraft\.item\.crafting\.FurnaceRecipes\.func_151397_a[^\n]+\s+at net\.minecraft\.item\.crafting\.FurnaceRecipes\.func_151398_b[^\n]+\s+at mezz\.jei\.plugins\.vanilla\.furnace\.SmeltingRecipe\.drawInfo
\[JEI\]: Null stacks\s+java\.lang\.NullPointerException\s+at mezz\.jei\.util\.StackHelper\.getAllSubtypes

How to fix it

  1. Update Just Enough Items (JEI) and CraftTweaker/MineTweaker to the latest versions available for your Minecraft version, as newer JEI builds include null-recipe protection for smelting tabs.
  2. If the crash happens when viewing the Smelting tab in JEI, check your `scripts/` folder for CraftTweaker furnace recipes (`furnace.addRecipe` or `furnace.remove`) that reference invalid, mistyped, or empty item IDs.
  3. If your log shows `[JEI]: Null stacks` above `MineTweakerMod.onServerStopped`, open `logs/fml-client-latest.log` or `logs/latest.log` and search upward for an earlier `FATAL` or `ERROR` stack trace—another mod crashed the server first and triggered the MineTweaker rollback.
  4. If no custom scripts are installed, binary-search recently added mods (such as custom tool or smelting addons) to find the mod registering a broken furnace recipe.
LoadersForge
SeverityStops the game
CategoryMod conflicts

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