Pixelmon server

[asaph]

[04:28:27] [Server thread/ERROR] [minecraft/MinecraftServer]: Encountered an unexpected exception
net.minecraftforge.fml.common.LoaderExceptionModCrash: Caught exception from Pixelmon (pixelmon)

Caused by: java.lang.NoSuchMethodError: net.minecraftforge.fml.relauncher.ReflectionHelper.getPrivateValue(Ljava/lang/Class;Ljava/lang/Object;Ljava/lang/String;Ljava/lang/String;)Ljava/lang/Object;
        at com.pixelmonmod.pixelmon.entities.pixelmon.EntityPixelmon.<clinit>(EntityPixelmon.java:91) ~[EntityPixelmon.class:?]
        at com.pixelmonmod.pixelmon.CommonProxy.registerInteractions(CommonProxy.java:220) ~[CommonProxy.class:?]
        at com.pixelmonmod.pixelmon.Pixelmon.init(Pixelmon.java:163) ~[Pixelmon.class:?]
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_211]
        at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_211]
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_211]
        at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.8.0_211]
        at net.minecraftforge.fml.common.FMLModContainer.handleModStateEvent(FMLModContainer.java:624) ~[forge-1.12.2-14.23.5.2768-universal.jar:?]
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_211]
        at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_211]
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_211]
        at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.8.0_211]
        at com.google.common.eventbus.Subscriber.invokeSubscriberMethod(Subscriber.java:91) ~[minecraft_server.1.12.2.jar:?]
        at com.google.common.eventbus.Subscriber$SynchronizedSubscriber.invokeSubscriberMethod(Subscriber.java:150) ~[minecraft_server.1.12.2.jar:?]
        at com.google.common.eventbus.Subscriber$1.run(Subscriber.java:76) ~[minecraft_server.1.12.2.jar:?]
        at com.google.common.util.concurrent.MoreExecutors$DirectExecutor.execute(MoreExecutors.java:399) ~[minecraft_server.1.12.2.jar:?]
        at com.google.common.eventbus.Subscriber.dispatchEvent(Subscriber.java:71) ~[minecraft_server.1.12.2.jar:?]
        at com.google.common.eventbus.Dispatcher$PerThreadQueuedDispatcher.dispatch(Dispatcher.java:116) ~[minecraft_server.1.12.2.jar:?]
        at com.google.common.eventbus.EventBus.post(EventBus.java:217) ~[minecraft_server.1.12.2.jar:?]
        at net.minecraftforge.fml.common.LoadController.sendEventToModContainer(LoadController.java:218) ~[forge-1.12.2-14.23.5.2768-universal.jar:?]
        at net.minecraftforge.fml.common.LoadController.propogateStateMessage(LoadController.java:196) ~[forge-1.12.2-14.23.5.2768-universal.jar:?]
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_211]
        at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_211]
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_211]
        at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.8.0_211]
        at com.google.common.eventbus.Subscriber.invokeSubscriberMethod(Subscriber.java:91) ~[minecraft_server.1.12.2.jar:?]
        at com.google.common.eventbus.Subscriber$SynchronizedSubscriber.invokeSubscriberMethod(Subscriber.java:150) ~[minecraft_server.1.12.2.jar:?]
        at com.google.common.eventbus.Subscriber$1.run(Subscriber.java:76) ~[minecraft_server.1.12.2.jar:?]
        at com.google.common.util.concurrent.MoreExecutors$DirectExecutor.execute(MoreExecutors.java:399) ~[minecraft_server.1.12.2.jar:?]
        at com.google.common.eventbus.Subscriber.dispatchEvent(Subscriber.java:71) ~[minecraft_server.1.12.2.jar:?]
        at com.google.common.eventbus.Dispatcher$PerThreadQueuedDispatcher.dispatch(Dispatcher.java:116) ~[minecraft_server.1.12.2.jar:?]
        at com.google.common.eventbus.EventBus.post(EventBus.java:217) ~[minecraft_server.1.12.2.jar:?]
        at net.minecraftforge.fml.common.LoadController.redirect$onPost$zza000(LoadController.java:553) ~[LoadController.class:?]
        at net.minecraftforge.fml.common.LoadController.distributeStateMessage(LoadController.java:135) ~[LoadController.class:?]
        at net.minecraftforge.fml.common.Loader.initializeMods(Loader.java:744) ~[Loader.class:?]
        at net.minecraftforge.fml.server.FMLServerHandler.finishServerLoading(FMLServerHandler.java:108) ~[FMLServerHandler.class:?]
        at net.minecraftforge.fml.common.FMLCommonHandler.onServerStarted(FMLCommonHandler.java:338) ~[FMLCommonHandler.class:?]
        at net.minecraft.server.dedicated.DedicatedServer.func_71197_b(DedicatedServer.java:219) ~[nz.class:?]
        at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:486) [MinecraftServer.class:?]
        at java.lang.Thread.run(Unknown Source) [?:1.8.0_211]
[04:28:27] [Server thread/INFO] [STDOUT]: [net.minecraft.crash.CrashReport:func_85057_a:300]: Negative index in crash report handler (0/5)
[04:28:27] [Server thread/ERROR] [minecraft/MinecraftServer]: This crash report has been saved to: C:\Users\Dove\Desktop\Pixelmon Server\.\crash-reports\crash-2019-08-04_04.28.27-server.txt
[04:28:27] [Server thread/INFO] [minecraft/MinecraftServer]: Stopping server
[04:28:27] [Server thread/INFO] [minecraft/MinecraftServer]: Saving worlds
[04:28:27] [Server thread/INFO] [FML]: The state engine was in incorrect state POSTINITIALIZATION and forced into state SERVER_STOPPED. Errors may have been discarded.
[04:28:27] [Server Shutdown Thread/INFO] [minecraft/MinecraftServer]: Stopping server
>
[04:28:27] [Server Shutdown Thread/INFO] [minecraft/MinecraftServer]: Saving worlds

 

Can someone tell me what the problem is? And how I can fix that.

Edited August 4, 2019 by asaph

[DaemonUmbra]

Check the Pixelmon website and make sure you're using the version of Forge that Pixelmon is designed to work with