I'm not sure what's wrong, exactly.

[LemonJamTart]

Hello! I am not new to Minecraft modding, and have been playing this wonderful game almost since it came out- which is why the error I'm getting right now is confounding me. I've never seen it before. I'm using the Twitch launcher to easily compile a personal modpack, and whenever I try to actually launch the game, the loader window doesn't even appear before I get a crash report. 

Spoiler

Unable to launch java.lang.reflect.InvocationTargetException 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:497) at net.minecraft.launchwrapper.Launch.launch(Launch.java:135) at net.minecraft.launchwrapper.Launch.main(Launch.java:28) Caused by: java.lang.NoClassDefFoundError: Could not initialize class net.minecraft.init.Items at net.minecraft.potion.PotionHelper.func_185207_a(PotionHelper.java:154) at net.minecraft.init.Bootstrap.func_151354_b(Bootstrap.java:504) at net.minecraft.client.Minecraft.<init>(Minecraft.java:365) at net.minecraft.client.main.Main.main(SourceFile:123) ... 6 more

(I don't know what the 6 more are. I don't know how to get them to appear, either.)

The Twitch launcher is admittedly a new setup to me, so maybe I did something wrong? But I'm not exactly sure what, since this error is telling me that the issue is with Minecraft itself. I've never encountered it before, and although I've seen errors similar to it, the issue is usually with CodeChickenCore and other such things that can have a profound impact on how the game functions. Any assistance would be wonderful.

I'm sorry, I'm very stupid. I figured out what the issue is. It's OptiFine.

Edited December 7, 2018 by LemonJamTart