Games : "java.lang.NullPointerException: group" when starting a world [on hold]

enter preformatted text hereWhenever I try to log into any servers or start a single player world on my Minecraft (1.8.3), I get a java error named

java.lang.NullPointerException: group

I have no idea what this means, let alone how to fix it. The first time this happened I just did a system restore and then the problem was fixed. But now it has reoccured and a system restore is not helping any more.

After doing some research I have only found coding problems with this 'error' in it. Never have I found something to do with Minecraft when I search this problem.

Here is a crash report after i tried to play singleplayer:

---- Minecraft Crash Report ----

// Hey, that tickles! Hehehe!

Time: 1/03/15 9:28 PM Description: Updating screen events

java.lang.IllegalStateException: failed to create a child event loop at io.netty.util.concurrent.MultithreadEventExecutorGroup.(MultithreadEventExecutorGroup.java:61) at io.netty.channel.MultithreadEventLoopGroup.(MultithreadEventLoopGroup.java:49) at io.netty.channel.nio.NioEventLoopGroup.(NioEventLoopGroup.java:61) at io.netty.channel.nio.NioEventLoopGroup.(NioEventLoopGroup.java:52) at rd.a(SourceFile:40) at rd.b(SourceFile:37) at up.c(SourceFile:10) at rc.a(SourceFile:104) at bsu.a(SourceFile:1914) at bwf.a(SourceFile:210) at bxf.a(SourceFile:342) at bwf.a(SourceFile:350) at bxf.k(SourceFile:405) at bxf.p(SourceFile:382) at bsu.r(SourceFile:1473) at bsu.as(SourceFile:877) at bsu.a(SourceFile:314) at net.minecraft.client.main.Main.main(SourceFile:120) Caused by: io.netty.channel.ChannelException: failed to open a new selector at io.netty.channel.nio.NioEventLoop.openSelector(NioEventLoop.java:128) at io.netty.channel.nio.NioEventLoop.(NioEventLoop.java:120) at io.netty.channel.nio.NioEventLoopGroup.newChild(NioEventLoopGroup.java:87) at io.netty.util.concurrent.MultithreadEventExecutorGroup.(MultithreadEventExecutorGroup.java:57) ... 17 more Caused by: java.io.IOException: Unable to establish loopback connection at sun.nio.ch.PipeImpl$Initializer.run(PipeImpl.java:101) at sun.nio.ch.PipeImpl$Initializer.run(PipeImpl.java:68) at java.security.AccessController.doPrivileged(Native Method) at sun.nio.ch.PipeImpl.(PipeImpl.java:170) at sun.nio.ch.SelectorProviderImpl.openPipe(SelectorProviderImpl.java:50) at java.nio.channels.Pipe.open(Pipe.java:155) at sun.nio.ch.WindowsSelectorImpl.(WindowsSelectorImpl.java:127) at sun.nio.ch.WindowsSelectorProvider.openSelector(WindowsSelectorProvider.java:44) at io.netty.channel.nio.NioEventLoop.openSelector(NioEventLoop.java:126) ... 20 more Caused by: java.net.SocketException: Permission denied: connect at sun.nio.ch.Net.connect0(Native Method) at sun.nio.ch.Net.connect(Net.java:457) at sun.nio.ch.Net.connect(Net.java:449) at sun.nio.ch.SocketChannelImpl.connect(SocketChannelImpl.java:647) at java.nio.channels.SocketChannel.open(SocketChannel.java:189) at sun.nio.ch.PipeImpl$Initializer$LoopbackConnector.run(PipeImpl.java:130) at sun.nio.ch.PipeImpl$Initializer.run(PipeImpl.java:83) ... 28 more

A detailed walkthrough of the error, its code path and all known details is as follows:

-- Head -- Stacktrace: at io.netty.util.concurrent.MultithreadEventExecutorGroup.(MultithreadEventExecutorGroup.java:61) at io.netty.channel.MultithreadEventLoopGroup.(MultithreadEventLoopGroup.java:49) at io.netty.channel.nio.NioEventLoopGroup.(NioEventLoopGroup.java:61) at io.netty.channel.nio.NioEventLoopGroup.(NioEventLoopGroup.java:52) at rd.a(SourceFile:40) at rd.b(SourceFile:37) at up.c(SourceFile:10) at rc.a(SourceFile:104) at bsu.a(SourceFile:1914) at bwf.a(SourceFile:210) at bxf.a(SourceFile:342) at bwf.a(SourceFile:350) at bxf.k(SourceFile:405) at bxf.p(SourceFile:382)

-- Affected screen -- Details: Screen name: bxq Stacktrace: at bsu.r(SourceFile:1473) at bsu.as(SourceFile:877) at bsu.a(SourceFile:314) at net.minecraft.client.main.Main.main(SourceFile:120)

-- System Details -- Details: Minecraft Version: 1.8 Operating System: Windows 7 (amd64) version 6.1 Java Version: 1.8.0_25, Oracle Corporation Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation Memory: 103571888 bytes (98 MB) / 333004800 bytes (317 MB) up to 1060372480 bytes (1011 MB) JVM Flags: 6 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx1G -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode -XX:-UseAdaptiveSizePolicy -Xmn128M IntCache: cache: 0, tcache: 0, allocated: 13, tallocated: 95 Launched Version: 1.8 LWJGL: 2.9.1 OpenGL: GeForce GT 540M/PCI/SSE2 GL version 4.1.0, NVIDIA Corporation GL Caps: Using GL 1.3 multitexturing. Using GL 1.3 texture combiners. Using framebuffer objects because OpenGL 3.0 is supported and separate blending is supported. Shaders are available because OpenGL 2.1 is supported. VBOs are available because OpenGL 1.5 is supported.

Using VBOs: No
Is Modded: Probably not. Jar signature remains and client brand is untouched.
Type: Client (map_client.txt)
Resource Packs: []
Current Language: English (US)
Profiler Position: N/A (disabled)