Forge 1.8.9 keeps crashing

[EnderDoug]

I've searched all over the internet for a solution but can't find anything. When I launch minecraft with forge it crashed and gives me an error message:

The crash report is:

 

---- Minecraft Crash Report ----
// Would you like a cupcake?

Time: 11/26/18 9:08 AM
Description: Unexpected error

java.lang.NoSuchMethodError: net.minecraft.server.MinecraftServer.func_184103_al()Lnet/minecraft/server/management/PlayerList;
    at com.sk89q.worldedit.forge.ThreadSafeCache.tickStart(ThreadSafeCache.java:61)
    at net.minecraftforge.fml.common.eventhandler.ASMEventHandler_6_ThreadSafeCache_tickStart_TickEvent.invoke(.dynamic)
    at net.minecraftforge.fml.common.eventhandler.ASMEventHandler.invoke(ASMEventHandler.java:55)
    at net.minecraftforge.fml.common.eventhandler.EventBus.post(EventBus.java:140)
    at net.minecraftforge.fml.common.FMLCommonHandler.onRenderTickStart(FMLCommonHandler.java:342)
    at net.minecraft.client.Minecraft.func_71411_J(Minecraft.java:1049)
    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)

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

-- System Details --
Details:
    Minecraft Version: 1.8.9
    Operating System: Mac OS X (x86_64) version 10.13.6
    Java Version: 1.8.0_74, Oracle Corporation
    Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
    Memory: 1318281000 bytes (1257 MB) / 1610612736 bytes (1536 MB) up to 3221225472 bytes (3072 MB)
    JVM Flags: 7 total; -Xmx3G -XX:+UnlockExperimentalVMOptions -XX:+UseG1GC -XX:G1NewSizePercent=20 -XX:G1ReservePercent=20 -XX:MaxGCPauseMillis=50 -XX:G1HeapRegionSize=32M
    IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
    FML: MCP 9.19 Powered by Forge 11.15.1.1722 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
    UCHIJA    mcp{9.19} [Minecraft Coder Pack] (minecraft.jar) 
    UCHIJA    FML{8.0.99.99} [Forge Mod Loader] (forge-1.8.9-11.15.1.1722.jar) 
    UCHIJA    Forge{11.15.1.1722} [Minecraft Forge] (forge-1.8.9-11.15.1.1722.jar) 
    UCHIJA    worldedit{6.1.8} [WorldEdit] (worldedit-forge-mc1.12-6.1.8-dist.jar) 
    Loaded coremods (and transformers): 
    Launched Version: 1.8.9-forge1.8.9-11.15.1.1722
    LWJGL: 2.9.2
    OpenGL: Intel(R) Iris(TM) Graphics 6100 GL version 2.1 INTEL-10.36.19, 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: Yes
    Is Modded: Definitely; Client brand changed to 'fml,forge'
    Type: Client (map_client.txt)
    Resource Packs: Short FaithFull, #Unphairs Lightmap
    Current Language: English (US)
    Profiler Position: N/A (disabled)
    CPU: 4x Intel(R) Core(TM) i5-5257U CPU @ 2.70GHz

 

If anyone has any clue to what is going on it would be GREATLY appreciated!

[diesieben07]

You installed World Edit for 1.12 on 1.8.9.

Stop using 1.8.9.

[Tom_Bomb1854]

i am sorry for wasting anyone's time i forgot i had a 1.15 mod activated

Edited July 16, 2020 by Tom_Bomb1854