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made a modpack but i get this error every time i try to launch minecraft

1.21.1

Posted 2 hours ago2 hr

[main/ERROR]:Failed reading REFMAP JSON from : java.lang.NullPointerException Cannot invoke "org.spongepowered.asm.mixin.refmap.ReferenceMapper.setResourceName(String)" because "mapper" is null

this is the error message i keep getting when trying to launch minecraft from the launcher with my mods but i just can't figure out what this error message means. i'm new to making mod packs but i have tried making 3 separate mod packs with different mods but i still run into this issue and i am starting to think there might be a conflict between 2 different mods but again i have no idea since this is the only error message i get. any idea's?

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made a modpack but i get this error every time i try to launch minecraft

[main/ERROR]:Failed reading REFMAP JSON from : java.lang.NullPointerException Cannot invoke "org.spongepowered.asm.mixin.refmap.ReferenceMapper.setResourceName(String)" because "mapper" is null

this is the error message i keep getting when trying to launch minecraft from the launcher with my mods but i just can't figure out what this error message means. i'm new to making mod packs but i have tried making 3 separate mod packs with different mods but i still run into this issue and i am starting to think there might be a conflict between 2 different mods but again i have no idea since this is the only error message i get. any idea's?

By shadcrow_OTD · Posted 2 hours ago2 hr
The game crashed: rendering overlay Error: com.electronwill.nightconfig.core.io.WritingException: An I/O error occured

Add the crash-report or latest.log (logs-folder) with sites like https://mclo.gs/ and paste the link to it here

By TileEntity · 13 hours ago13 hr
The game crashed: rendering overlay Error: com.electronwill.nightconfig.core.io.WritingException: An I/O error occured

i have downloaded a mod called All in One (Modded One Block) and downloaded it through essentials mod to play with my friends, it starts to load up and start loading into the game but then i get the crash report and get sent back to the launcher with the error code "The game crashed: rendering overlay Error: com.electronwill.nightconfig.core.io.WritingException: An I/O error occured".

By Qtincy · Posted 14 hours ago14 hr
How Do I Commission A Mod

There typically isnt a place to commission mods. Mods are made by hobbyist programmers in their spair time. You could try some general minecraft modding discords, but I dont have any to recommend.

By LexManos · 21 hours ago21 hr
jarJar not working

minecraftLibrary is required for dev time for it to load.
jarJar should be enough for runtime.
be sure you're running the latest forge. And make sure you post your debug log.

By LexManos · 21 hours ago21 hr

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made a modpack but i get this error every time i try to launch minecraft

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made a modpack but i get this error every time i try to launch minecraft

The game crashed: rendering overlay Error: com.electronwill.nightconfig.core.io.WritingException: An I/O error occured

The game crashed: rendering overlay Error: com.electronwill.nightconfig.core.io.WritingException: An I/O error occured

How Do I Commission A Mod

jarJar not working

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