ClientCommandHandler#registerCommand does not exist

[Redempt]

Title says it all. I'm trying to make an alias mod, and it uses client commands. In my testing environment (gradle runClient) the mod works fine, but in my actual client (version 1.12.2 - 14.23.2.2611) it throws a NoSuchMethodError, saying ClientCommandHandler#registerCommand doesn't exist. I'd tried to make this mod a while back and encountered the exact same error, and I have absolutely no idea why it's happening.

 

Crash report:

https://hastebin.com/xogevejupe.rb

The only other mod I had installed at the time of that crashed was BestSprinting, a togglesprint mod I made.

[Choonster]

How did you build your mod? You need to build it using the build Gradle task, which reobfuscates your mod to SRG names (the names used by Forge outside of the development environment) after building it.

[Redempt]

Oh, I was using "jar."

[Redempt]

It works now, thanks! It's now saying that I don't have permission to use the command, but I'm assuming I just need to override the checkPermission method. I'll post here again if that doesn't work.