Describe the bug
Crash when opening an already existing mod.

To Reproduce
Steps to reproduce the behavior:
You probably won't be able to because this crash occurs on a modpack that hasn't been released yet. Although I managed to get a crashy report here :
https://crashy.net/YDkRnNF4ng2clQcU7iOW

Version information (please complete the following information):

• AntiqueAtlas: antiqueatlas-5.4.4-forge
• Minecraft: 1.16.5
• Forge: 36.2.9
  The crashy report already sums up anything you need to know on my specs, that tool si pretty handy maybe you'll recognize an error in the report

Also, launching again the world right after the crash (with notenoughcrashes for example) doesn't trigger another crash, the level starts.
Thank you for your amazing work, if you get any ideas about why this is happening really anything could help right now 👍

Duplicate of #314

That has been fixed for a while now. Please update.