forge not working

[crazywillbear]

i cant open my multimc instance with forge installed. when i uninstall forge, it launches with no problem.

 

It said this:

[17:14:31] [main/ERROR]: Unable to launch

java.lang.RuntimeException: FML was unable to install the security manager. The game will not start

at net.minecraftforge.fml.common.launcher.FMLTweaker.<init>(FMLTweaker.java:58) ~[forge-1.12.2-14.23.5.2854-universal.jar:?]

at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[?:1.8.0_261]

at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source) ~[?:1.8.0_261]

at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source) ~[?:1.8.0_261]

at java.lang.reflect.Constructor.newInstance(Unknown Source) ~[?:1.8.0_261]

at java.lang.Class.newInstance(Unknown Source) ~[?:1.8.0_261]

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:?]

at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_261]

at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_261]

at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_261]

at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.8.0_261]

at org.multimc.onesix.OneSixLauncher.launchWithMainClass(OneSixLauncher.java:196) [NewLaunch.jar:?]

at org.multimc.onesix.OneSixLauncher.launch(OneSixLauncher.java:231) [NewLaunch.jar:?]

at org.multimc.EntryPoint.listen(EntryPoint.java:143) [NewLaunch.jar:?]

at org.multimc.EntryPoint.main(EntryPoint.java:34) [NewLaunch.jar:?]

Caused by: java.lang.SecurityException

Process exited with code 1

[DaemonUmbra]

1.12 is no longer supported on this forum.

Please update to a modern version of Minecraft to receive support.