Minecraft Forums

So previously I was having an issue with my Minecraft Launcher & Java here I had to uninstall java and reinstall it (I installed the latest version, 8) and delete everything in my .minecraft folder except my save/saves file. Launched Minecraft and the issue was fixed.

Sadly the same isn't for Forge 1.8.9 and it is having issues trying to read something (my guess)

[19:11:53] [main/INFO]: Loading tweak class name net.minecraftforge.fml.common.launcher.FMLTweaker
[19:11:53] [main/ERROR]: Unable to launch
java.lang.ClassNotFoundException: net.minecraftforge.fml.common.launcher.FMLTweaker
	at java.net.URLClassLoader$1.run(Unknown Source) ~[?:1.7.0_80]
	at java.net.URLClassLoader$1.run(Unknown Source) ~[?:1.7.0_80]
	at java.security.AccessController.doPrivileged(Native Method) ~[?:1.7.0_80]
	at java.net.URLClassLoader.findClass(Unknown Source) ~[?:1.7.0_80]
	at java.lang.ClassLoader.loadClass(Unknown Source) ~[?:1.7.0_80]
	at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source) ~[?:1.7.0_80]
	at java.lang.ClassLoader.loadClass(Unknown Source) ~[?:1.7.0_80]
	at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:106) ~[launchwrapper-1.12.jar:?]
	at java.lang.ClassLoader.loadClass(Unknown Source) ~[?:1.7.0_80]
	at java.lang.ClassLoader.loadClass(Unknown Source) ~[?:1.7.0_80]
	at java.lang.Class.forName0(Native Method) ~[?:1.7.0_80]
	at java.lang.Class.forName(Unknown Source) ~[?:1.7.0_80]
	at net.minecraft.launchwrapper.Launch.launch(Launch.java:98) [launchwrapper-1.12.jar:?]
	at net.minecraft.launchwrapper.Launch.main(Launch.java:28) [launchwrapper-1.12.jar:?]

I tried to use a older version of Java, I ended up choosing Java 7 since that worked out best with me before when I had a similar issue like this. I uninstalled Java & reinstalled Java 7, tested out if it would launch and it did not work. However Vanilla Minecraft works fine.

Is there a way to fix this issue?

Edit: Issue is fixed. Changed the forge version and it reinstalled the recommended version. Works perfectly now,

For Java 7 at least haven't tested Java 8.

You may need to reinstall the locally installed files that Minecraft puts into place.
To do so, press your Windows+R keys, type in %AppData% at the dialog, and press Enter. In the window that appears, open the .minecraft directory, and delete everything except for the saves directory that you see therein. Then, try running Minecraft again. Good luck!
[/pre]





[header=r]