[This is my friend's issue, he can't sign up on Jira]

When loading a world (singleplayer/multiplayer) the game crashes with the follwing log:

---- Minecraft Crash Report ---- // Surprise! Haha. Well, this is awkward. Time: 05.11.2021, 18:52 Description: mouseClicked event handler java.lang.IllegalStateException: failed to create a child event loop at io.netty.util.concurrent.MultithreadEventExecutorGroup.<init>(MultithreadEventExecutorGroup.java:88) at io.netty.util.concurrent.MultithreadEventExecutorGroup.<init>(MultithreadEventExecutorGroup.java:58) at io.netty.util.concurrent.MultithreadEventExecutorGroup.<init>(MultithreadEventExecutorGroup.java:47) at io.netty.channel.MultithreadEventLoopGroup.<init>(MultithreadEventLoopGroup.java:59) at io.netty.channel.nio.NioEventLoopGroup.<init>(NioEventLoopGroup.java:77) at io.netty.channel.nio.NioEventLoopGroup.<init>(NioEventLoopGroup.java:72) at io.netty.channel.nio.NioEventLoopGroup.<init>(NioEventLoopGroup.java:59) at aci.f(SourceFile:56) at com.google.common.base.Suppliers$NonSerializableMemoizingSupplier.get(Suppliers.java:160) at agx.a(SourceFile:19) at aci.a(SourceFile:148) at dvp.a(SourceFile:2083) at dvp.a(SourceFile:1939) at eel$a.h(SourceFile:437) at eel$a.b(SourceFile:343) at eel$a.a(SourceFile:274) at dww.a(SourceFile:359) at dxx.a(SourceFile:27) at dvq.b(SourceFile:94) at eaq.a(SourceFile:490) at dvq.a(SourceFile:94) at dvq.c(SourceFile:165) at aqv.execute(SourceFile:101) at dvq.b(SourceFile:165) at org.lwjgl.glfw.GLFWMouseButtonCallbackI.callback(GLFWMouseButtonCallbackI.java:36) at org.lwjgl.system.JNI.invokeV(Native Method) at org.lwjgl.glfw.GLFW.glfwPollEvents(GLFW.java:3101) at com.mojang.blaze3d.systems.RenderSystem.flipFrame(SourceFile:172) at dpr.e(SourceFile:310) at dvp.f(SourceFile:1137) at dvp.e(SourceFile:728) at net.minecraft.client.main.Main.main(SourceFile:217) Caused by: io.netty.channel.ChannelException: failed to open a new selector at io.netty.channel.nio.NioEventLoop.openSelector(NioEventLoop.java:177) at io.netty.channel.nio.NioEventLoop.<init>(NioEventLoop.java:151) at io.netty.channel.nio.NioEventLoopGroup.newChild(NioEventLoopGroup.java:127) at io.netty.channel.nio.NioEventLoopGroup.newChild(NioEventLoopGroup.java:36) at io.netty.util.concurrent.MultithreadEventExecutorGroup.<init>(MultithreadEventExecutorGroup.java:84) ... 31 more Caused by: java.io.IOException: Unable to establish loopback connection at java.base/sun.nio.ch.PipeImpl$Initializer.run(PipeImpl.java:101) at java.base/sun.nio.ch.PipeImpl$Initializer.run(PipeImpl.java:67) at java.base/java.security.AccessController.doPrivileged(AccessController.java:554) at java.base/sun.nio.ch.PipeImpl.<init>(PipeImpl.java:194) at java.base/sun.nio.ch.WindowsSelectorImpl.<init>(WindowsSelectorImpl.java:143) at java.base/sun.nio.ch.WindowsSelectorProvider.openSelector(WindowsSelectorProvider.java:44) at io.netty.channel.nio.NioEventLoop.openSelector(NioEventLoop.java:175) ... 35 more Caused by: java.net.SocketException: Invalid argument: connect at java.base/sun.nio.ch.UnixDomainSockets.connect0(Native Method) at java.base/sun.nio.ch.UnixDomainSockets.connect(UnixDomainSockets.java:146) at java.base/sun.nio.ch.UnixDomainSockets.connect(UnixDomainSockets.java:142) at java.base/sun.nio.ch.SocketChannelImpl.connect(SocketChannelImpl.java:849) at java.base/java.nio.channels.SocketChannel.open(SocketChannel.java:285) at java.base/sun.nio.ch.PipeImpl$Initializer$LoopbackConnector.run(PipeImpl.java:131) at java.base/sun.nio.ch.PipeImpl$Initializer.run(PipeImpl.java:83) ... 41 more A detailed walkthrough of the error, its code path and all known details is as follows: --------------------------------------------------------------------------------------- – Head – Thread: Render thread Stacktrace: at io.netty.util.concurrent.MultithreadEventExecutorGroup.<init>(MultithreadEventExecutorGroup.java:88) at io.netty.util.concurrent.MultithreadEventExecutorGroup.<init>(MultithreadEventExecutorGroup.java:58) at io.netty.util.concurrent.MultithreadEventExecutorGroup.<init>(MultithreadEventExecutorGroup.java:47) at io.netty.channel.MultithreadEventLoopGroup.<init>(MultithreadEventLoopGroup.java:59) at io.netty.channel.nio.NioEventLoopGroup.<init>(NioEventLoopGroup.java:77) at io.netty.channel.nio.NioEventLoopGroup.<init>(NioEventLoopGroup.java:72) at io.netty.channel.nio.NioEventLoopGroup.<init>(NioEventLoopGroup.java:59) at aci.f(SourceFile:56) at com.google.common.base.Suppliers$NonSerializableMemoizingSupplier.get(Suppliers.java:160) at agx.a(SourceFile:19) at aci.a(SourceFile:148) at dvp.a(SourceFile:2083) at dvp.a(SourceFile:1939) at eel$a.h(SourceFile:437) at eel$a.b(SourceFile:343) at eel$a.a(SourceFile:274) at dww.a(SourceFile:359) at dxx.a(SourceFile:27) at dvq.b(SourceFile:94)

I know there is already a report on this, but the fix method from there didn't help. Reinstalled MC four times, (I don't use antivirus), nothing.