my MultiMC problem

MultiMC version: 0.7.0-4233


Launched instance in online mode

sessionserver.mojang.com resolves to:
    [13.107.253.67, 2620:1ec:29:1::67]

textures.minecraft.net resolves to:
    [13.107.253.67, 2620:1ec:29:1::67]

api.minecraftservices.com resolves to:
    [13.107.253.67, 2620:1ec:29:1::67]


Minecraft folder is:
/home/frederica-bernkastel/.local/share/multimc/instances/1.5.2 mody/.minecraft


Java path is:
/usr/bin/java


Checking Java version...
Java is version 17.0.15, using amd64 architecture, from Arch Linux.


AMD Ryzen 5 5600H with Radeon Graphics
NVIDIA Corporation GA106M [GeForce RTX 3060 Mobile / Max-Q] (rev a1)

Subsystem: Lenovo Device 3a81

Kernel driver in use: nvidia

OpenGL version string: 4.6.0 NVIDIA 575.64.03

Main Class:


Native path:
  /home/frederica-bernkastel/.local/share/multimc/instances/1.5.2 mody/natives

Traits:
traits legacyFML
traits texturepacks
traits legacyLaunch

Libraries:
  /home/frederica-bernkastel/.local/share/multimc/libraries/net/java/jinput/jinput/2.0.5/jinput-2.0.5.jar
  /home/frederica-bernkastel/.local/share/multimc/libraries/net/java/jutils/jutils/1.0.0/jutils-1.0.0.jar
  /home/frederica-bernkastel/.local/share/multimc/libraries/org/lwjgl/lwjgl/lwjgl/2.9.4-nightly-20150209/lwjgl-2.9.4-nightly-20150209.jar
  /home/frederica-bernkastel/.local/share/multimc/libraries/org/lwjgl/lwjgl/lwjgl_util/2.9.4-nightly-20150209/lwjgl_util-2.9.4-nightly-20150209.jar
  /home/frederica-bernkastel/.local/share/multimc/instances/1.5.2 mody/.minecraft/bin/minecraft.jar

Native libraries:
  /home/frederica-bernkastel/.local/share/multimc/libraries/net/java/jinput/jinput-platform/2.0.5/jinput-platform-2.0.5-natives-linux.jar
  /home/frederica-bernkastel/.local/share/multimc/libraries/org/lwjgl/lwjgl/lwjgl-platform/2.9.4-nightly-20150209/lwjgl-platform-2.9.4-nightly-20150209-natives-linux.jar

Jar Mods:
  forge-1.5.2-7.8.1.738-universal.jar

Params:


Window size: 854 x 480

Java Arguments:
[-Dfml.ignoreInvalidMinecraftCertificates=true, -Dfml.ignorePatchDiscrepancies=true, -Xms512m, -Xmx1024m, -Duser.language=en]


Minecraft process ID: 195409


Using onesix launcher.

Launching with applet wrapper...
Applet wrapper failed:
java.lang.ClassCastException: class jdk.internal.loader.ClassLoaders$AppClassLoader cannot be cast to class java.net.URLClassLoader (jdk.internal.loader.ClassLoaders$AppClassLoader and java.net.URLClassLoader are in module java.base of loader 'bootstrap')

Falling back to using main class.
	at cpw.mods.fml.relauncher.FMLRelauncher.<init>(FMLRelauncher.java:60)
	at cpw.mods.fml.relauncher.FMLRelauncher.instance(FMLRelauncher.java:52)
	at cpw.mods.fml.relauncher.FMLRelauncher.appletEntry(FMLRelauncher.java:229)
	at net.minecraft.client.MinecraftApplet.init(MinecraftApplet.java:25)
	at net.minecraft.Launcher.init(Launcher.java:109)
	at org.multimc.LegacyFrame.start(LegacyFrame.java:130)
	at org.multimc.onesix.OneSixLauncher.legacyLaunch(OneSixLauncher.java:147)
	at org.multimc.onesix.OneSixLauncher.launch(OneSixLauncher.java:273)
	at org.multimc.EntryPoint.listen(EntryPoint.java:143)
	at org.multimc.EntryPoint.main(EntryPoint.java:34)
Failed to invoke the Minecraft main class:
java.lang.ClassCastException: class jdk.internal.loader.ClassLoaders$AppClassLoader cannot be cast to class java.net.URLClassLoader (jdk.internal.loader.ClassLoaders$AppClassLoader and java.net.URLClassLoader are in module java.base of loader 'bootstrap')
	at cpw.mods.fml.relauncher.FMLRelauncher.<init>(FMLRelauncher.java:60)
	at cpw.mods.fml.relauncher.FMLRelauncher.instance(FMLRelauncher.java:52)
	at cpw.mods.fml.relauncher.FMLRelauncher.handleClientRelaunch(FMLRelauncher.java:38)
	at net.minecraft.client.Minecraft.main(Minecraft.java:2237)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
Exiting with -1
	at java.base/java.lang.reflect.Method.invoke(Method.java:569)
	at org.multimc.onesix.OneSixLauncher.legacyLaunch(OneSixLauncher.java:164)
	at org.multimc.onesix.OneSixLauncher.launch(OneSixLauncher.java:273)
	at org.multimc.EntryPoint.listen(EntryPoint.java:143)
	at org.multimc.EntryPoint.main(EntryPoint.java:34)
Process exited with exit code 255 (0xff).
Please note that usually neither the exit code, nor its description are enough to diagnose issues!
Always upload the entire log and not just the exit code.
Clipboard copy at: 26 Jul 2025 23:06:06 +0000