A few days earlier I've sent a ticket already, but when I replied to the sent email no one replied yet... Sorry for disturbing... I tried to join with only Pixelmon, doesn't work, I tried to join without ANY mods, doesn't work. Here is the crash report:

---- Minecraft Crash Report ----

WARNING: coremods are present:
Java8CheckerCoremod (Pixelmon-1.8.9-4.3.0-beta8-universal.jar)
Contact their authors BEFORE contacting forge

// But it works on my machine.

Time: 9/20/16 5:08 PM
Description: Updating screen events

io.netty.channel.ChannelException: connection refused
at io.netty.channel.local.LocalChannel$LocalUnsafe.connect(LocalChannel.java:373)
at io.netty.channel.DefaultChannelPipeline$HeadContext.connect(DefaultChannelPipeline.java:1029)
at io.netty.channel.AbstractChannelHandlerContext.invokeConnect(AbstractChannelHandlerContext.java:496)
at io.netty.channel.AbstractChannelHandlerContext.connect(AbstractChannelHandlerContext.java:481)
at io.netty.channel.AbstractChannelHandlerContext.connect(AbstractChannelHandlerContext.java:463)
at io.netty.channel.DefaultChannelPipeline.connect(DefaultChannelPipeline.java:849)
at io.netty.channel.AbstractChannel.connect(AbstractChannel.java:199)
at io.netty.bootstrap.Bootstrap$2.run(Bootstrap.java:187)
at io.netty.channel.local.LocalEventLoop.run(LocalEventLoop.java:33)
at io.netty.util.concurrent.SingleThreadEventExecutor$2.run(SingleThreadEventExecutor.java:116)
at java.lang.Thread.run(Thread.java:745)


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

-- Head --
Stacktrace:
at io.netty.channel.local.LocalChannel$LocalUnsafe.connect(LocalChannel.java:373)

-- Affected screen --
Details:
Screen name: net.minecraft.client.gui.GuiMainMenu
Stacktrace:
at net.minecraft.client.Minecraft.func_71407_l(Minecraft.java:1679)
at net.minecraft.client.Minecraft.func_71411_J(Minecraft.java:1024)
at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:349)
at net.minecraft.client.main.Main.main(SourceFile:124)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at net.minecraft.launchwrapper.Launch.launch(Launch.java:135)
at net.minecraft.launchwrapper.Launch.main(Launch.java:28)

-- System Details --
Details:
Minecraft Version: 1.8.9
Operating System: Mac OS X (x86_64) version 10.11.6
Java Version: 1.8.0_74, Oracle Corporation
Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
Memory: 497504160 bytes (474 MB) / 2038431744 bytes (1944 MB) up to 3817865216 bytes (3641 MB)
JVM Flags: 1 total; -Xmx4G
IntCache: cache: 0, tcache: 0, allocated: 13, tallocated: 95
FML: MCP 9.19 Powered by Forge 11.15.1.1902 4 mods loaded, 4 mods active
States: 'U' = Unloaded 'L' = Loaded 'C' = Constructed 'H' = Pre-initialized 'I' = Initialized 'J' = Post-initialized 'A' = Available 'D' = Disabled 'E' = Errored
UCHIJAAAAA mcp{9.19} [Minecraft Coder Pack] (minecraft.jar)
UCHIJAAAAA FML{8.0.99.99} [Forge Mod Loader] (forge-1.8.9-11.15.1.1902-1.8.9.jar)
UCHIJAAAAA Forge{11.15.1.1902} [Minecraft Forge] (forge-1.8.9-11.15.1.1902-1.8.9.jar)
UCHIJAAAAA pixelmon{4.3.0-beta8} [Pixelmon] (Pixelmon-1.8.9-4.3.0-beta8-universal.jar)
Loaded coremods (and transformers):
Java8CheckerCoremod (Pixelmon-1.8.9-4.3.0-beta8-universal.jar)

Launched Version: 1.8.9-forge1.8.9-11.15.1.1902-1.8.9
LWJGL: 2.9.2
OpenGL: Intel(R) Iris(TM) Graphics 6100 GL version 2.1 INTEL-10.14.73, Intel Inc.
GL Caps: Using GL 1.3 multitexturing.
Using GL 1.3 texture combiners.
Using framebuffer objects because ARB_framebuffer_object 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: Definitely; Client brand changed to 'fml,forge'
Type: Client (map_client.txt)
Resource Packs: §f§lInFinite 16x §8§l1.8 §6§l[V1.2]
Current Language: English (UK)
Profiler Position: N/A (disabled)
CPU: 4x Intel(R) Core(TM) i5-5257U CPU @ 2.70GHz

Nothing in that crash report relates to us. Its crashing on the mainmenu for some reason. Try removing the resource pack you have installed. That's the only thing that i can see from that crash report.

It still doesn't work... I've worked quite hard on that world and would prefer not deleting anything or mess anything from the folder, any other ideas on how I can fix this problem? Thanks,
Marcus