Start script generated by ServerPackCreator dev. To change the launch settings of this server, such as JVM args / flags, Minecraft version, modloader version etc., edit the variables.txt-file. Detected 1.21.8 - Java 21 Running NeoForge checks and setup... Generating user_jvm_args.txt from variables... Edit JAVA_ARGS in your variables.txt. Do not edit user_jvm_args.txt directly! Manually made changes to user_jvm_args.txt will be lost in the nether! server.jar present. Starting server... Minecraft version: 1.21.8 Modloader: NeoForge Modloader version: 21.8.54 LegacyFabric Installer Version: 1.1.1 Fabric Installer Version: 1.1.2 Quilt Installer Version: 0.15.1 Java Args: Additional Args: -Dlog4j2.formatMsgNoLookups=true SSJ Forge Args: -Djava.security.manager=allow Java Path: /opt/java-21/bin/java Wait For User Input: false Run Command: /opt/java-21/bin/java -Dlog4j2.formatMsgNoLookups=true @user_jvm_args.txt -jar server.jar --installer-force --installer 21.8.54 nogui Java version: openjdk version "21.0.12.1" 2026-08-18 LTS OpenJDK Runtime Environment Temurin-21.0.12.1+1 (build 21.0.12.1+1-LTS) OpenJDK 64-Bit Server VM Temurin-21.0.12.1+1 (build 21.0.12.1+1-LTS, mixed mode, sharing) Failed to compute version of installer: neoforge-21.8.54-installer.jar [11:45:13] [main/INFO]: ModLauncher running: args [--launchTarget, neoforgeserver, --fml.neoForgeVersion, 21.8.54, --fml.fmlVersion, 9.0.18, --fml.mcVersion, 1.21.8, --fml.neoFormVersion, 20250717.133445, nogui] [11:45:13] [main/INFO]: JVM identified as Eclipse Adoptium OpenJDK 64-Bit Server VM 21.0.12.1+1-LTS [11:45:13] [main/INFO]: ModLauncher 9.0 starting: java version 21.0.12.1 by Eclipse Adoptium; OS Linux arch amd64 version 5.15.0-1114-realtime [11:45:13] [main/INFO]: ImmediateWindowProvider not loading because launch target is neoforgeserver [11:45:13] [main/INFO]: SpongePowered MIXIN Subsystem Version=0.8.7 Source=union:/srv/pack/libraries/net/fabricmc/sponge-mixin/0.15.2+mixin.0.8.7/sponge-mixin-0.15.2+mixin.0.8.7.jar%2388!/ Service=ModLauncher Env=SERVER [11:45:14] [main/INFO]: Found mod file "server-1.21.8-20250717.133445-srg.jar" [locator: production server provider +net.neoforged:neoforge:21.8.54:server] [11:45:14] [main/INFO]: Found mod file "neoforge-21.8.54-universal.jar" [locator: PathBasedLocator[name=neoforge, paths=[libraries/net/neoforged/neoforge/21.8.54/neoforge-21.8.54-universal.jar]], reader: mod manifest] [11:45:14] [main/INFO]: Found mod file "constantmusic-neoforge-1.0.6+mc1.21.8.jar" [locator: {mods folder locator at /srv/pack/mods}, reader: mod manifest] [11:45:14] [main/INFO]: Found 2 dependencies adding them to mods collection [11:45:14] [main/INFO]: Found gamelibrary file "mixinextras-neoforge-0.5.3.jar" [parent: neoforge-21.8.54-universal.jar, locator: jarinjar, reader: mod manifest] [11:45:14] [main/INFO]: Found library file "net.neoforged.neoforge-coremods-21.8.54.jar" [parent: neoforge-21.8.54-universal.jar, locator: jarinjar, reader: mod manifest] [11:45:14] [main/INFO]: Mod List: Name Version (Mod Id) Constant Music 1.0.6 (constantmusic) Minecraft 1.21.8 (minecraft) NeoForge 21.8.54 (neoforge) [11:45:15] [main/INFO]: Compatibility level set to JAVA_21 [11:45:15] [main/INFO]: Launching target 'neoforgeserver' with arguments [nogui] 2026-09-28T11:45:15.232458014Z main WARN Advanced terminal features are not available in this environment [11:45:15] [main/WARN] [mixin/]: Reference map 'constantmusic.refmap.json' for constantmusic.neoforge.mixins.json could not be read. If this is a development environment you can ignore this message [11:45:15] [main/WARN] [mixin/]: Reference map 'constantmusic.refmap.json' for constantmusic.common.mixins.json could not be read. If this is a development environment you can ignore this message [11:45:16] [main/INFO] [MixinExtras|Service/]: Initializing MixinExtras via com.llamalad7.mixinextras.service.MixinExtrasServiceImpl(version=0.5.3). [11:45:23] [modloading-worker-0/ERROR] [ne.ne.fm.ja.FMLModContainer/LOADING]: Failed to create mod instance. ModID: constantmusic, class com.odinokland.constantmusic.neoforge.ConstantMusicNeoForge java.lang.NoClassDefFoundError: net/minecraft/client/OptionInstance$ValueSet at TRANSFORMER/constantmusic@1.0.6/com.odinokland.constantmusic.neoforge.ConstantMusicNeoForge.(ConstantMusicNeoForge.java:32) ~[constantmusic-neoforge-1.0.6+mc1.21.8.jar%23146!/:?] {re:classloading} at java.base/jdk.internal.reflect.DirectConstructorHandleAccessor.newInstance(DirectConstructorHandleAccessor.java:62) ~[?:?] {} at java.base/java.lang.reflect.Constructor.newInstanceWithCaller(Constructor.java:502) ~[?:?] {} at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:486) ~[?:?] {} at MC-BOOTSTRAP/fml_loader@9.0.18/net.neoforged.fml.javafmlmod.FMLModContainer.constructMod(FMLModContainer.java:118) ~[loader-9.0.18.jar%2372!/:9.0] {} at MC-BOOTSTRAP/fml_loader@9.0.18/net.neoforged.fml.ModLoader.lambda$constructMods$3(ModLoader.java:151) ~[loader-9.0.18.jar%2372!/:9.0] {} at MC-BOOTSTRAP/fml_loader@9.0.18/net.neoforged.fml.ModLoader.lambda$dispatchParallelTask$7(ModLoader.java:229) ~[loader-9.0.18.jar%2372!/:9.0] {} at java.base/java.util.concurrent.CompletableFuture.uniHandle(CompletableFuture.java:934) [?:?] {} at java.base/java.util.concurrent.CompletableFuture$UniHandle.tryFire(CompletableFuture.java:911) [?:?] {} at java.base/java.util.concurrent.CompletableFuture$Completion.exec(CompletableFuture.java:483) [?:?] {} at java.base/java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:387) [?:?] {} at java.base/java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(ForkJoinPool.java:1312) [?:?] {} at java.base/java.util.concurrent.ForkJoinPool.scan(ForkJoinPool.java:1843) [?:?] {} at java.base/java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1808) [?:?] {} at java.base/java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:188) [?:?] {} Caused by: java.lang.ClassNotFoundException: net.minecraft.client.OptionInstance$ValueSet at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:641) ~[?:?] {} at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:526) ~[?:?] {} at cpw.mods.securejarhandler/cpw.mods.cl.ModuleClassLoader.loadClass(ModuleClassLoader.java:228) ~[securejarhandler-9.0.18.jar:?] {} at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:526) ~[?:?] {} at cpw.mods.securejarhandler/cpw.mods.cl.ModuleClassLoader.loadClass(ModuleClassLoader.java:228) ~[securejarhandler-9.0.18.jar:?] {} at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:526) ~[?:?] {} ... 15 more [11:45:23] [modloading-worker-0/INFO] [ne.ne.ne.co.NeoForgeMod/NEOFORGE-MOD]: NeoForge mod loading, version 21.8.54, for MC 1.21.8 [11:45:23] [main/FATAL] [ne.ne.fm.ModLoader/LOADING]: Failed to wait for future Mod Construction, 1 errors found [11:45:23] [main/ERROR] [minecraft/CrashReport]: Negative index in crash report handler (0/25) [11:45:23] [main/FATAL] [ne.ne.ne.co.NeoForgeMod/]: Preparing crash report with UUID df109d96-4aec-4625-9c6d-423010381627 [11:45:23] [main/FATAL] [ne.ne.ne.se.lo.ServerModLoader/]: Crash report saved to ./crash-reports/crash-2026-09-28_11.45.23-fml.txt [11:45:23] [main/FATAL] [ne.ne.ne.co.NeoForgeMod/]: Preparing crash report with UUID f6eec9b6-70d9-4432-bb5d-f70d44ab1b2a ---- Minecraft Crash Report ---- // Why did you do that? Time: 2026-09-28 11:45:23 Description: Mod loading failures have occurred; consult the issue messages for more details net.neoforged.neoforge.logging.CrashReportExtender$ModLoadingCrashException: Mod loading has failed A detailed walkthrough of the error, its code path and all known details is as follows: --------------------------------------------------------------------------------------- -- Head -- Thread: main Stacktrace: at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:641) ~[?:?] {} -- Mod loading issue for: constantmusic -- Details: Caused by 0: java.lang.NoClassDefFoundError: net/minecraft/client/OptionInstance$ValueSet at TRANSFORMER/constantmusic@1.0.6/com.odinokland.constantmusic.neoforge.ConstantMusicNeoForge.(ConstantMusicNeoForge.java:32) ~[constantmusic-neoforge-1.0.6+mc1.21.8.jar%23146!/:?] {re:classloading} at java.base/jdk.internal.reflect.DirectConstructorHandleAccessor.newInstance(DirectConstructorHandleAccessor.java:62) ~[?:?] {} at java.base/java.lang.reflect.Constructor.newInstanceWithCaller(Constructor.java:502) ~[?:?] {} at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:486) ~[?:?] {} at MC-BOOTSTRAP/fml_loader@9.0.18/net.neoforged.fml.javafmlmod.FMLModContainer.constructMod(FMLModContainer.java:118) ~[loader-9.0.18.jar%2372!/:9.0] {} at MC-BOOTSTRAP/fml_loader@9.0.18/net.neoforged.fml.ModLoader.lambda$constructMods$3(ModLoader.java:151) ~[loader-9.0.18.jar%2372!/:9.0] {} at MC-BOOTSTRAP/fml_loader@9.0.18/net.neoforged.fml.ModLoader.lambda$dispatchParallelTask$7(ModLoader.java:229) ~[loader-9.0.18.jar%2372!/:9.0] {} at java.base/java.util.concurrent.CompletableFuture.uniHandle(CompletableFuture.java:934) ~[?:?] {} at java.base/java.util.concurrent.CompletableFuture$UniHandle.tryFire(CompletableFuture.java:911) ~[?:?] {} at java.base/java.util.concurrent.CompletableFuture$Completion.exec(CompletableFuture.java:483) ~[?:?] {} at java.base/java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:387) ~[?:?] {} at java.base/java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(ForkJoinPool.java:1312) ~[?:?] {} at java.base/java.util.concurrent.ForkJoinPool.scan(ForkJoinPool.java:1843) ~[?:?] {} at java.base/java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1808) ~[?:?] {} at java.base/java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:188) ~[?:?] {} Mod file: /srv/pack/mods/constantmusic-neoforge-1.0.6+mc1.21.8.jar Failure message: Constant Music (constantmusic) has failed to load correctly java.lang.NoClassDefFoundError: net/minecraft/client/OptionInstance$ValueSet Mod version: 1.0.6 Mod issues URL: https://github.com/odinokland/constant-music/issues Exception message: java.lang.ClassNotFoundException: net.minecraft.client.OptionInstance$ValueSet Stacktrace: at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:641) ~[?:?] {} at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:526) ~[?:?] {} at cpw.mods.securejarhandler/cpw.mods.cl.ModuleClassLoader.loadClass(ModuleClassLoader.java:228) ~[securejarhandler-9.0.18.jar:?] {} at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:526) ~[?:?] {} at cpw.mods.securejarhandler/cpw.mods.cl.ModuleClassLoader.loadClass(ModuleClassLoader.java:228) ~[securejarhandler-9.0.18.jar:?] {} at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:526) ~[?:?] {} at TRANSFORMER/constantmusic@1.0.6/com.odinokland.constantmusic.neoforge.ConstantMusicNeoForge.(ConstantMusicNeoForge.java:32) ~[constantmusic-neoforge-1.0.6+mc1.21.8.jar%23146!/:?] {re:classloading} at java.base/jdk.internal.reflect.DirectConstructorHandleAccessor.newInstance(DirectConstructorHandleAccessor.java:62) ~[?:?] {} at java.base/java.lang.reflect.Constructor.newInstanceWithCaller(Constructor.java:502) ~[?:?] {} at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:486) ~[?:?] {} at MC-BOOTSTRAP/fml_loader@9.0.18/net.neoforged.fml.javafmlmod.FMLModContainer.constructMod(FMLModContainer.java:118) ~[loader-9.0.18.jar%2372!/:9.0] {} at MC-BOOTSTRAP/fml_loader@9.0.18/net.neoforged.fml.ModLoader.lambda$constructMods$3(ModLoader.java:151) ~[loader-9.0.18.jar%2372!/:9.0] {} at MC-BOOTSTRAP/fml_loader@9.0.18/net.neoforged.fml.ModLoader.lambda$dispatchParallelTask$7(ModLoader.java:229) ~[loader-9.0.18.jar%2372!/:9.0] {} at java.base/java.util.concurrent.CompletableFuture.uniHandle(CompletableFuture.java:934) ~[?:?] {} at java.base/java.util.concurrent.CompletableFuture$UniHandle.tryFire(CompletableFuture.java:911) ~[?:?] {} at java.base/java.util.concurrent.CompletableFuture$Completion.exec(CompletableFuture.java:483) ~[?:?] {} at java.base/java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:387) ~[?:?] {} at java.base/java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(ForkJoinPool.java:1312) ~[?:?] {} at java.base/java.util.concurrent.ForkJoinPool.scan(ForkJoinPool.java:1843) ~[?:?] {} at java.base/java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1808) ~[?:?] {} at java.base/java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:188) ~[?:?] {} -- System Details -- Details: Minecraft Version: 1.21.8 Minecraft Version ID: 1.21.8 Operating System: Linux (amd64) version 5.15.0-1114-realtime Java Version: 21.0.12.1, Eclipse Adoptium Java VM Version: OpenJDK 64-Bit Server VM (mixed mode, sharing), Eclipse Adoptium Memory: 160956416 bytes (153 MiB) / 277872640 bytes (265 MiB) up to 805306368 bytes (768 MiB) CPUs: 2 Processor Vendor: GenuineIntel Processor Name: Intel(R) Core(TM) i9-9900K CPU @ 3.60GHz Identifier: Intel64 Family 6 Model 158 Stepping 12 Microarchitecture: Coffee Lake Frequency (GHz): 3.60 Number of physical packages: 1 Number of physical CPUs: 8 Number of logical CPUs: 16 Graphics card #0 name: unknown Graphics card #0 vendor: unknown Graphics card #0 VRAM (MiB): 0.00 Graphics card #0 deviceId: unknown Graphics card #0 versionInfo: unknown Virtual memory max (MiB): 68454.64 Virtual memory used (MiB): 28247.77 Swap memory total (MiB): 4096.00 Swap memory used (MiB): 1624.95 Space in storage for jna.tmpdir (MiB): Space in storage for org.lwjgl.system.SharedLibraryExtractPath (MiB): Space in storage for io.netty.native.workdir (MiB): Space in storage for java.io.tmpdir (MiB): available: 64358.52, total: 64358.65 Space in storage for workdir (MiB): available: 2251012.25, total: 7564391.00 JVM Flags: 0 total; ModLauncher: 9.0 ModLauncher launch target: neoforgeserver ModLauncher services: sponge-mixin-0.15.2+mixin.0.8.7.ja r mixin PLUGINSERVICE loader-9.0.18.jar neoforgedevdistcleaner PLUGINSERVICE loader-9.0.18.jar slf4jfixer PLUGINSERVICE loader-9.0.18.jar runtime_enum_extender PLUGINSERVICE loader-9.0.18.jar accesstransformer PLUGINSERVICE loader-9.0.18.jar mixin TRANSFORMATIONSERVICE loader-9.0.18.jar fml TRANSFORMATIONSERVICE FML Language Providers: javafml@9.0 minecraft@9.0 Mod List: constantmusic-neoforge-1.0.6+mc1.21.8.jar |Constant Music |constantmusic |1.0.6 |Manifest: NOSIGNATURE server-1.21.8-20250717.133445-srg.jar |Minecraft |minecraft |1.21.8 |Manifest: NOSIGNATURE neoforge-21.8.54-universal.jar |NeoForge |neoforge |21.8.54 |Manifest: NOSIGNATURE Crash Report UUID: f6eec9b6-70d9-4432-bb5d-f70d44ab1b2a FML: 9.0.18 NeoForge: 21.8.54 [11:45:23] [main/ERROR] [minecraft/Main]: Failed to start the minecraft server net.neoforged.fml.ModLoadingException: Loading errors encountered: - Constant Music (constantmusic) has failed to load correctly java.lang.NoClassDefFoundError: net/minecraft/client/OptionInstance$ValueSet at MC-BOOTSTRAP/fml_loader@9.0.18/net.neoforged.fml.ModLoader.waitForFuture(ModLoader.java:279) ~[loader-9.0.18.jar%2372!/:9.0] {} at MC-BOOTSTRAP/fml_loader@9.0.18/net.neoforged.fml.ModLoader.dispatchParallelTask(ModLoader.java:242) ~[loader-9.0.18.jar%2372!/:9.0] {} at MC-BOOTSTRAP/fml_loader@9.0.18/net.neoforged.fml.ModLoader.constructMods(ModLoader.java:150) ~[loader-9.0.18.jar%2372!/:9.0] {} at MC-BOOTSTRAP/fml_loader@9.0.18/net.neoforged.fml.ModLoader.gatherAndInitializeMods(ModLoader.java:140) ~[loader-9.0.18.jar%2372!/:9.0] {} at TRANSFORMER/neoforge@21.8.54/net.neoforged.neoforge.internal.CommonModLoader.begin(CommonModLoader.java:49) ~[neoforge-21.8.54-universal.jar%23145!/:?] {re:classloading} at TRANSFORMER/neoforge@21.8.54/net.neoforged.neoforge.server.loading.ServerModLoader.load(ServerModLoader.java:29) ~[neoforge-21.8.54-universal.jar%23145!/:?] {re:classloading} at TRANSFORMER/minecraft@1.21.8/net.minecraft.server.Main.main(Main.java:120) ~[server-1.21.8-20250717.133445-srg.jar%23144!/:?] {re:classloading} at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103) ~[?:?] {} at java.base/java.lang.reflect.Method.invoke(Method.java:580) ~[?:?] {} at MC-BOOTSTRAP/fml_loader@9.0.18/net.neoforged.fml.loading.targets.CommonLaunchHandler.runTarget(CommonLaunchHandler.java:132) ~[loader-9.0.18.jar%2372!/:9.0] {} at MC-BOOTSTRAP/fml_loader@9.0.18/net.neoforged.fml.loading.targets.CommonLaunchHandler.serverService(CommonLaunchHandler.java:124) ~[loader-9.0.18.jar%2372!/:9.0] {} at MC-BOOTSTRAP/fml_loader@9.0.18/net.neoforged.fml.loading.targets.NeoForgeServerLaunchHandler.runService(NeoForgeServerLaunchHandler.java:41) ~[loader-9.0.18.jar%2372!/:9.0] {} at MC-BOOTSTRAP/fml_loader@9.0.18/net.neoforged.fml.loading.targets.CommonLaunchHandler.lambda$launchService$4(CommonLaunchHandler.java:114) ~[loader-9.0.18.jar%2372!/:9.0] {} at MC-BOOTSTRAP/fml_loader@9.0.18/cpw.mods.modlauncher.LaunchServiceHandlerDecorator.launch(LaunchServiceHandlerDecorator.java:25) [loader-9.0.18.jar%2372!/:9.0] {} at MC-BOOTSTRAP/fml_loader@9.0.18/cpw.mods.modlauncher.LaunchServiceHandler.launch(LaunchServiceHandler.java:55) [loader-9.0.18.jar%2372!/:9.0] {} at MC-BOOTSTRAP/fml_loader@9.0.18/cpw.mods.modlauncher.LaunchServiceHandler.launch(LaunchServiceHandler.java:73) [loader-9.0.18.jar%2372!/:9.0] {} at MC-BOOTSTRAP/fml_loader@9.0.18/cpw.mods.modlauncher.Launcher.run(Launcher.java:104) [loader-9.0.18.jar%2372!/:9.0] {} at MC-BOOTSTRAP/fml_loader@9.0.18/cpw.mods.modlauncher.Launcher.main(Launcher.java:75) [loader-9.0.18.jar%2372!/:9.0] {} at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103) ~[?:?] {} at java.base/java.lang.reflect.Method.invoke(Method.java:580) ~[?:?] {} at cpw.mods.bootstraplauncher/cpw.mods.bootstraplauncher.BootstrapLauncher.run(BootstrapLauncher.java:203) [bootstraplauncher-9.0.18.jar:?] {} at cpw.mods.bootstraplauncher/cpw.mods.bootstraplauncher.BootstrapLauncher.main(BootstrapLauncher.java:62) [bootstraplauncher-9.0.18.jar:?] {} at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103) ~[?:?] {} at java.base/java.lang.reflect.Method.invoke(Method.java:580) ~[?:?] {} at net.neoforged.serverstarterjar.Main.mainLaunch(Main.java:306) [server.jar:0.1.35] {} at net.neoforged.serverstarterjar.Main.main(Main.java:76) [server.jar:0.1.35] {} at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103) ~[?:?] {} at java.base/java.lang.reflect.Method.invoke(Method.java:580) ~[?:?] {} at net.neoforged.serverstarterjar.Main8.main(Main8.java:19) [server.jar:0.1.35] {} Exiting...