Modpack Just keeps Crashing when i try to launch it

Hi, I’m building a 1.16.5 modpack intended for a small group of friends, but it just crashes a good 10 seconds into loading. and with no obvious log or easy way to tell what mod it is. i’ve tried disabling mods but that doesn’t change anything. i would really appreciate help from someone who Knows more about modding than me



So a mod is using Sponge’s Mixin library, but you havent got Sponge itself meaning that support will be lacking at best.

From what it looks like, Mixins it attempting to look for a class (file) that doesnt exist, however your log is filtered so its hard to tell.

The somewhat good news is, if you cannot get a helpful response, you maybe able to find the culprate, or at least a list of potentional culprates. You can do this by the following

  1. Change the .jar of all your mods to .zip (if you have winzip, 7zip or winrar, you can skip this step)

  2. Open/extract a zip file (if you have winzip, 7zip, winrar, just right click → open with → program)

  3. Here you will see a lot of folders, look for a folder called “org”, if it doesnt have one then that mod isnt responsible for the crash)

  4. Open the folder “org”. If it has “spongepowered” then this could be one of the mods causing the issue, if spongepowered is not present then that mod is not a issue.

  5. if you changed to a zip and extracted, then clean up the generated files from the extract

  6. repeate with the next mod

This should give you a filtered list of potentional mod issues, from there you can take a look at those mods websites/github for issues relating to “Mixin crashes” and/or check for updates of that mod.

Hope that helps and remeber that while Sponge makes Mixins, it is the mod host who is responsible for what that mod supports, not Sponge.

Think i managed to find the Mod causing the problem. and it now launches just fine, Thank you for your help!

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