Lizzycloudgirl

I've figured out what has been making me crash. It's a mod called Decocraft.

When I try to play Minecraft Forge 1.12.2 it instantly crashes. I don't know how to paste the file for the report so here it is (copy & pasted) : ---- Minecraft Crash Report ---- // Who set us up the TNT? Time: 6/22/19 2:36 PM Description: Initializing game java.lang.NoClassDefFoundError: com/mia/craftstudio/IPackReaderCallback at java.lang.Class.forName0(Native Method) at java.lang.Class.forName(Class.java:348) at net.minecraftforge.fml.common.FMLModContainer.constructMod(FMLModContainer.java:539) at sun.reflect.NativeMethodAcc

So when I try to load up minecraft it crashes before I can even get into the game. I am trying to use Forge 1.12.2. The crash notice says, "It looks like you are using an unsupported modified version of the game. The game crashed whilst initializing game." What should I do? Also, how do I add the crash report?