Attempting to update to 9.2.6 from 9.2.5

World Started normally
Server crashed on pokemon battle (first move)

Unable to downgrade back to 9.2.6.
Need to restore 'World' folder

java.lang.NoClassDefFoundError: org/apache/commons/compress/utils/Lists
at com.pixelmonmod.pixelmon.battles.attacks.Attack.redirectAttackToNewTarget(Attack.java:611) ~[Pixelmon-1.20.2-9.2.6-server.jar%2397!/:9.2.6-pipe22672] {re:classloading}
at com.pixelmonmod.pixelmon.battles.attacks.Attack.use(Attack.java:373) ~[Pixelmon-1.20.2-9.2.6-server.jar%2397!/:9.2.6-pipe22672] {re:classloading}
at com.pixelmonmod.pixelmon.battles.controller.participants.PixelmonWrapper.useAttack(PixelmonWrapper.java:1042) ~[Pixelmon-1.20.2-9.2.6-server.jar%2397!/:9.2.6-pipe22672] {re:classloading}
at com.pixelmonmod.pixelmon.battles.controller.participants.PixelmonWrapper.useAttack(PixelmonWrapper.java:976) ~[Pixelmon-1.20.2-9.2.6-server.jar%2397!/:9.2.6-pipe22672] {re:classloading}
at com.pixelmonmod.pixelmon.battles.controller.participants.PixelmonWrapper.takeTurn(PixelmonWrapper.java:1848) ~[Pixelmon-1.20.2-9.2.6-server.jar%2397!/:9.2.6-pipe22672] {re:classloading}
at com.pixelmonmod.pixelmon.battles.controller.BattleController.takeTurn(BattleController.java:1438) ~[Pixelmon-1.20.2-9.2.6-server.jar%2397!/:9.2.6-pipe22672] {re:classloading}
at com.pixelmonmod.pixelmon.battles.controller.BattleController.doTurnLogic(BattleController.java:619) ~[Pixelmon-1.20.2-9.2.6-server.jar%2397!/:9.2.6-pipe22672] {re:classloading}
at com.pixelmonmod.pixelmon.battles.controller.BattleController.update(BattleController.java:539) ~[Pixelmon-1.20.2-9.2.6-server.jar%2397!/:9.2.6-pipe22672] {re:classloading}
at com.pixelmonmod.pixelmon.battles.BattleRegistry.updateBattles(BattleRegistry.java:273) ~[Pixelmon-1.20.2-9.2.6-server.jar%2397!/:9.2.6-pipe22672] {re:classloading}
at com.pixelmonmod.pixelmon.battles.BattleTickHandler.tickStart(BattleTickHandler.java:13) ~[Pixelmon-1.20.2-9.2.6-server.jar%2397!/:9.2.6-pipe22672] {re:classloading}
at com.pixelmonmod.pixelmon.battles.__BattleTickHandler_tickStart_LevelTickEvent.invoke(.dynamic) ~[Pixelmon-1.20.2-9.2.6-server.jar%2397!/:9.2.6-pipe22672] {re:classloading,pl:eventbus:B}
at net.minecraftforge.eventbus.ASMEventHandler.invoke(ASMEventHandler.java:58) ~[eventbus-6.2.0.jar%2349!/:?] {}
at net.minecraftforge.eventbus.EventBus.post(EventBus.java:300) ~[eventbus-6.2.0.jar%2349!/:?] {}
at net.minecraftforge.eventbus.EventBus.post(EventBus.java:281) ~[eventbus-6.2.0.jar%2349!/:?] {}
at net.minecraftforge.event.ForgeEventFactory.post(ForgeEventFactory.java:170) ~[forge-1.20.2-48.1.0-universal.jar%23104!/:?] {re:classloading}
at net.minecraftforge.event.ForgeEventFactory.onPostLevelTick(ForgeEventFactory.java:739) ~[forge-1.20.2-48.1.0-universal.jar%23104!/:?] {re:classloading}
at net.minecraft.server.MinecraftServer.m_5703_(MinecraftServer.java:900) ~[server-1.20.2-20230921.100330-srg.jar%2399!/:?] {re:classloading,pl:accesstransformer:B}
at net.minecraft.server.dedicated.DedicatedServer.m_5703_(DedicatedServer.java:283) ~[server-1.20.2-20230921.100330-srg.jar%2399!/:?] {re:classloading,pl:accesstransformer:B}
at net.minecraft.server.MinecraftServer.m_5705_(MinecraftServer.java:809) ~[server-1.20.2-20230921.100330-srg.jar%2399!/:?] {re:classloading,pl:accesstransformer:B}
at net.minecraft.server.MinecraftServer.m_130011_(MinecraftServer.java:656) ~[server-1.20.2-20230921.100330-srg.jar%2399!/:?] {re:classloading,pl:accesstransformer:B}
at net.minecraft.server.MinecraftServer.m_206580_(MinecraftServer.java:249) ~[server-1.20.2-20230921.100330-srg.jar%2399!/:?] {re:classloading,pl:accesstransformer:B}
at java.lang.Thread.run(Thread.java:842) ~[?:?] {}
Caused by: java.lang.ClassNotFoundException: org.apache.commons.compress.utils.Lists
at jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:641) ~[?:?] {}
at java.lang.ClassLoader.loadClass(ClassLoader.java:520) ~[?:?] {}
at net.minecraftforge.securemodules.SecureModuleClassLoader.loadClass(SecureModuleClassLoader.java:392) ~[securemodules-2.2.3.jar:?] {}
at java.lang.ClassLoader.loadClass(ClassLoader.java:520) ~[?:?] {}
at net.minecraftforge.securemodules.SecureModuleClassLoader.loadClass(SecureModuleClassLoader.java:392) ~[securemodules-2.2.3.jar:?] {}
at java.lang.ClassLoader.loadClass(ClassLoader.java:520) ~[?:?] {}
... 22 more

Thanks for the report, I was able to confirm this issue. Moving to internal

How soon will the problem be resolved? Or is there any way we can manually fix it?

Unfortunately there's no ETA or temporary fix at the moment apart from attempting to downgrade to 9.2.5. It's important to note 9.2.x is an alpha version, so be aware issues like this can happen.

Is there an update on the progress of this ticket?

Here's a temporary unofficial sidemod to resolve this for now: https://github.com/DThaiPome/NowYouCanBattleAgain_Jar/releases Please ensure this is removed when the bug is officially fixed to prevent any further issues. Closing this ticket as this is resolved for next update.