[1.15.2] [Solved] Development build works fine, but production build crashes?

[FireController1847]

I am currently developing a mod using Minecraft Forge 31.2.0 for Minecraft 1.15.2, with the mappings of snapshot-20200518-1.15.1. I am using IntelliJ as my environment.

When I launch my mod using the IntelliJRuns, it works great. Everything works fine with no issues at all. So, I run the "jar" gradle task and get my jar out of it. This is where things go awry. I install the same version of Forge onto vanilla MC using the vanilla launcher, and it fails to load. This is a crash report submitted by one of my users: https://pastebin.com/eckCHVvF . I get the same crash report when getting it. Something along the lines of .maxStackSize is not a method when making a new item, but that doesn't make sense because it is a method (though for those who want to see my code, here's my item class that it's erroring on: https://hastebin.com/rilexoduro.java ).

So, I'm at a complete loss. I have no idea why it would be crashing like this. It builds and runs fine in my development environment, but when I generate the JAR for some reason it crashes in a production environment. I've tried completely rebuilding my gradle cache, resetting my IntelliJ, and straight up deleting everything and re-starting from my GitHub repository ( https://gitlab.com/FireController1847/levelhearts/ ) all to no avail. So, I come here. Does this ring a bell for anyone? Is anyone else getting this error? Does somebody have any idea as to what might be happening? Because I'm clueless.

[ChampionAsh5357]

My guess is that the jar file didn't obfuscate itself to match what the actual method is (e.g. func_numbers_letter). The command I use is 'gradlew build' which is what I assume is what you are doing. You might need to either try a different version mapping or source version.

[FireController1847]

12 minutes ago, ChampionAsh5357 said:

My guess is that the jar file didn't obfuscate itself to match what the actual method is (e.g. func_numbers_letter). The command I use is 'gradlew build' which is what I assume is what you are doing. You might need to either try a different version mapping or source version.

I'm going to be honest with you, I have no idea what I was thinking. I've been running "gradlew jar" not "gradlew build". It works great now, thanks!