Cant Update my mod to Neoforge/ Does Not Exist

I attempted to update my mod to the new version 1.20.4, but this seems to have corrupted all the items in my mod. When I downgrade to version 1.20.1 Forge it works, but this is the only version that works. I used plugins to see if I could downgrade the mod, which resulted in a slightly better outcome. In versions 1.19.4 and 1.19.2 only all entities were "corrupted," but the same error apears does not matter the version "Does not exist" message keeps repeating itself, along with occasional "recursive constructor invocation" errors. I can't update my mod or continue support for old versions.

Things I've already tried that didn't work:

- Regenerating the code and build
- Clearing all Gradle caches
- Debugging the client
- Deleting the build file and restarting the PC
- Reloading the Gradle project
- Exporting the workspace and trying on another file
- Creating a new workspace and trying the same thing, then going back to the original one
- Changing the code myself and locking the elements

Here is the Crash Log: https://justpaste.it/6zmhs
Here is the workspace: https://drive.google.com/drive/folders/1UnRfnEswf1U7MkRh1H2QLk3mij2hkuJ…

Please any kind of support would be very appreciated here