FAQ

Q: There's a popup saying "Java Development Kit not found!" when I try to run jar. How do I fix it?
A: Make sure that the default java on your PC is a JDK, not a JRE. Alternatively if you don't want to change the default, you can run CLI with java that you want

Q: I need to decompile <insert any mod>. How can I do that?
A: Run setup for vanilla version that the mod is for. Replace minecraft.jar in jars folder with the one that has the mod installed. Decompile.

Q: I'm getting errors after decompiling a mod. What should I do?
A: Fix all compilation errors in source and run Update MD5 task when you are done.