As the title says, I have been able to run the mod in my IDE successfully and test it. Whenever I build the mod and run it with the current modpack I'm testing, I get this: Initializing game java.lang.NoSuchMethodError: net.minecraft.block.Block.setCreativeTab.

 

Here is the crash report with the offending code. I'm kinda lost as to why this is happening now of all times.

Spoiler

---- Minecraft Crash Report ----

WARNING: coremods are present:
  AppleCore (AppleCore-mc1.12.2-3.1.3.jar)
Contact their authors BEFORE contacting forge

// I bet Cylons wouldn't have this problem.

Time: 9/8/19 7:18 PM
Description: Initializing game

java.lang.NoSuchMethodError: net.minecraft.block.Block.setCreativeTab(Lnet/minecraft/creativetab/CreativeTabs;)Lnet/minecraft/block/Block;
    at com.cilka.telgt.Utils.AddBlocksToTab(Utils.java:88)
    at com.cilka.telgt.init.ModBlocks.<clinit>(ModBlocks.java:12)
    at sun.misc.Unsafe.ensureClassInitialized(Native Method)
    at sun.reflect.UnsafeFieldAccessorFactory.newFieldAccessor(UnsafeFieldAccessorFactory.java:43)
    at sun.reflect.ReflectionFactory.newFieldAccessor(ReflectionFactory.java:156)
    at java.lang.reflect.Field.acquireFieldAccessor(Field.java:1088)
    at java.lang.reflect.Field.getFieldAccessor(Field.java:1069)
    at java.lang.reflect.Field.get(Field.java:393)
    at com.cilka.telgt.EventSubscriber.registerBlocks(EventSubscriber.java:51)
    at net.minecraftforge.fml.common.eventhandler.ASMEventHandler_119_EventSubscriber_registerBlocks_Register.invoke(.dynamic)
    at net.minecraftforge.fml.common.eventhandler.ASMEventHandler.invoke(ASMEventHandler.java:90)
    at net.minecraftforge.fml.common.eventhandler.EventBus$1.invoke(EventBus.java:144)
    at net.minecraftforge.fml.common.eventhandler.EventBus.post(EventBus.java:182)
    at net.minecraftforge.registries.GameData.fireRegistryEvents(GameData.java:775)
    at net.minecraftforge.fml.common.Loader.preinitializeMods(Loader.java:628)
    at net.minecraftforge.fml.client.FMLClientHandler.beginMinecraftLoading(FMLClientHandler.java:252)
    at net.minecraft.client.Minecraft.func_71384_a(Minecraft.java:466)
    at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:377)
    at net.minecraft.client.main.Main.main(SourceFile:123)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at net.minecraft.launchwrapper.Launch.launch(Launch.java:135)
    at net.minecraft.launchwrapper.Launch.main(Launch.java:28)

A detailed walkthrough of the error, its code path and all known details is as follows:
---------------------------------------------------------------------------------------

-- Head --
Thread: Client thread
Stacktrace:
    at com.cilka.telgt.Utils.AddBlocksToTab(Utils.java:88)
    at com.cilka.telgt.init.ModBlocks.<clinit>(ModBlocks.java:12)
    at sun.misc.Unsafe.ensureClassInitialized(Native Method)
    at sun.reflect.UnsafeFieldAccessorFactory.newFieldAccessor(UnsafeFieldAccessorFactory.java:43)
    at sun.reflect.ReflectionFactory.newFieldAccessor(ReflectionFactory.java:156)
    at java.lang.reflect.Field.acquireFieldAccessor(Field.java:1088)
    at java.lang.reflect.Field.getFieldAccessor(Field.java:1069)
    at java.lang.reflect.Field.get(Field.java:393)
    at com.cilka.telgt.EventSubscriber.registerBlocks(EventSubscriber.java:51)
    at net.minecraftforge.fml.common.eventhandler.ASMEventHandler_119_EventSubscriber_registerBlocks_Register.invoke(.dynamic)
    at net.minecraftforge.fml.common.eventhandler.ASMEventHandler.invoke(ASMEventHandler.java:90)
    at net.minecraftforge.fml.common.eventhandler.EventBus$1.invoke(EventBus.java:144)
    at net.minecraftforge.fml.common.eventhandler.EventBus.post(EventBus.java:182)
    at net.minecraftforge.registries.GameData.fireRegistryEvents(GameData.java:775)
    at net.minecraftforge.fml.common.Loader.preinitializeMods(Loader.java:628)
    at net.minecraftforge.fml.client.FMLClientHandler.beginMinecraftLoading(FMLClientHandler.java:252)
    at net.minecraft.client.Minecraft.func_71384_a(Minecraft.java:466)

-- Initialization --
Details:
Stacktrace:
    at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:377)
    at net.minecraft.client.main.Main.main(SourceFile:123)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at net.minecraft.launchwrapper.Launch.launch(Launch.java:135)
    at net.minecraft.launchwrapper.Launch.main(Launch.java:28)

public static BaseBlock[] AddBlocksToTab(BaseBlock[] blocks, CreativeTabs tab)
	{
		for(Block block : blocks)
		{
			block.setCreativeTab(tab);
		}
		return blocks;
	}

 

Here is the link to my github in case this does not have enough depth https://github.com/Cilka/Telgttatium/tree/master/java/com/cilka/telgt .

That worked, thanks!