I make my mod with IntelliJ and runClient didn't tell me any issue.

However, after I build the mod using gradlew build and run it on Forge 36.1.0, it cannot load into world with the mod as it says datapack error. I looked at the log, and the error originates from RecipeManager.fromJson and it's an AbstractMethodError. I noticed that it is about my recipe serializer, so I tried a lot of stuff with it. It runs well on IntelliJ without any error or datapack warning, but when it comes to a Forge profile (36.1.0), it just emits error when loading into worlds, including world creation.

I have no idea what's going on, but here are the things I'm going to try,

1. Use an updated version of Forge (in Minecraft launcher)
2. Run in another clean profile

(Just tried both. They failed.)

Edited April 3, 20214 yr by NorthWestWind
Actaully tried.

I just went to search for more and I came across this

Although it is for 1.8, I'm suspecting this is causing the issue.

Edited April 3, 20214 yr by NorthWestWind

I'm still trying to fix it. I duped my project and now trying to run/compile with minimal modification.

I found the problem.

It turns out to be an external library I declared in build.gradle. When I removed the dependency and compile, the mod finally runs in client.