Launching a VANILLA Minecraft Jar

[HorizonCode]

I Try to run a normal vanilla 1.8 Version but there is no GameType.Vanilla :/

My Code: http://horizonco.de/paste/?p=Bz1j2

[06:55:16 ERROR]: Unable to launch java.lang.ClassCastException: net.minecraft.client.main.Main cannot be cast to net.minecraft.launchwrapper.ITweaker at net.minecraft.launchwrapper.Launch.launch(Launch.java:98) [bin/:?] at net.minecraft.launchwrapper.Launch.main(Launch.java:28) [bin/:?] at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_131] at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_131] at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_131] at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.8.0_131] at fr.theshark34.openlauncherlib.internal.InternalLauncher.launch(InternalLauncher.java:166) [openlauncherlib-3.0.3-BETA.jar:?] at net.cube.Launcher.start(Launcher.java:33) [bin/:?] at net.cube.CubeController$8.run(CubeController.java:763) [bin/:?]

[Jeerrryyyy]

Hey Horizon. Maybe you can awnser here how you fixed it? I'am struggling with the same problem at the time. Would be nice if you can help.

[HorizonCode]

just set the GameTweak to null

[tikaros]

Doesn't work... https://hatebin.com/fjcbtimdjq