I've been trying to set up a 1.18.2 server and kept getting the same error message whenever booting up the server, it didn't matter how I changed the mods, the only time the server would start was without mods. I also tried running an older Forge server of mine (1.16.5), which I was able to run some time ago but now I got this exact same error message. It has something to do with SpongeForge and Mixin and even though the mods don't use it, the server wouldn't start at all without it, so just deleting the file doesn't work.

 

E:\Everything\Minecraft\Servers\Modded SmallMC 1.18.2>java @user_jvm_args.txt @libraries/net/minecraftforge/forge/1.18.2-40.2.0/win_args.txt  -nogui
2023-03-17 10:38:03,677 main WARN Advanced terminal features are not available in this environment
[10:38:03] [main/INFO] [cp.mo.mo.Launcher/MODLAUNCHER]: ModLauncher running: args [--launchTarget, forgeserver, --fml.forgeVersion, 40.2.0, --fml.mcVersion, 1.18.2, --fml.forgeGroup, net.minecraftforge, --fml.mcpVersion, 20220404.173914, -nogui]
[10:38:03] [main/INFO] [cp.mo.mo.Launcher/MODLAUNCHER]: ModLauncher 9.1.3+9.1.3+main.9b69c82a starting: java version 19.0.2 by Oracle Corporation
[10:38:03] [main/INFO] [mixin/]: SpongePowered MIXIN Subsystem Version=0.8.5 Source=union:/E:/Everything/Minecraft/Servers/Modded%20SmallMC%201.18.2/libraries/org/spongepowered/mixin/0.8.5/mixin-0.8.5.jar%2314!/ Service=ModLauncher Env=SERVER
[10:38:04] [main/WARN] [ne.mi.fm.lo.mo.ModFileParser/LOADING]: Mod file E:\Everything\Minecraft\Servers\Modded SmallMC 1.18.2\libraries\net\minecraftforge\fmlcore\1.18.2-40.2.0\fmlcore-1.18.2-40.2.0.jar is missing mods.toml file
[10:38:04] [main/WARN] [ne.mi.fm.lo.mo.ModFileParser/LOADING]: Mod file E:\Everything\Minecraft\Servers\Modded SmallMC 1.18.2\libraries\net\minecraftforge\javafmllanguage\1.18.2-40.2.0\javafmllanguage-1.18.2-40.2.0.jar is missing mods.toml file
[10:38:04] [main/WARN] [ne.mi.fm.lo.mo.ModFileParser/LOADING]: Mod file E:\Everything\Minecraft\Servers\Modded SmallMC 1.18.2\libraries\net\minecraftforge\lowcodelanguage\1.18.2-40.2.0\lowcodelanguage-1.18.2-40.2.0.jar is missing mods.toml file
[10:38:04] [main/WARN] [ne.mi.fm.lo.mo.ModFileParser/LOADING]: Mod file E:\Everything\Minecraft\Servers\Modded SmallMC 1.18.2\libraries\net\minecraftforge\mclanguage\1.18.2-40.2.0\mclanguage-1.18.2-40.2.0.jar is missing mods.toml file
[10:38:04] [main/INFO] [ne.mi.fm.lo.mo.JarInJarDependencyLocator/]: No dependencies to load found. Skipping!
[10:38:05] [main/INFO] [mixin/]: Compatibility level set to JAVA_17
[10:38:05] [main/INFO] [cp.mo.mo.LaunchServiceHandler/MODLAUNCHER]: Launching target 'forgeserver' with arguments [-nogui]
[10:38:05] [main/WARN] [mixin/]: Error loading class: java/lang/invoke/MethodHandles$Lookup (java.lang.IllegalArgumentException: Unsupported class file major version 63)
[10:38:05] [main/WARN] [mixin/]: Error loading class: java/lang/invoke/MethodHandles$Lookup (java.lang.IllegalArgumentException: Unsupported class file major version 63)
[10:38:05] [main/WARN] [mixin/]: Error loading class: java/util/Map$Entry (java.lang.IllegalArgumentException: Unsupported class file major version 63)
[10:38:05] [main/WARN] [mixin/]: Error loading class: java/lang/invoke/MethodHandles$Lookup (java.lang.IllegalArgumentException: Unsupported class file major version 63)
[10:38:05] [main/WARN] [mixin/]: Error loading class: java/lang/invoke/MethodHandles$Lookup (java.lang.IllegalArgumentException: Unsupported class file major version 63)
[10:38:05] [main/WARN] [mixin/]: Error loading class: java/lang/Record (java.lang.IllegalArgumentException: Unsupported class file major version 63)
[10:38:05] [main/WARN] [mixin/]: Error loading class: java/util/Set (java.lang.IllegalArgumentException: Unsupported class file major version 63)
Exception in thread "main" org.spongepowered.asm.mixin.transformer.throwables.MixinTransformerError: An unexpected critical error was encountered
        at MC-BOOTSTRAP/org.spongepowered.mixin/org.spongepowered.asm.mixin.transformer.MixinProcessor.applyMixins(MixinProcessor.java:392)
        at MC-BOOTSTRAP/org.spongepowered.mixin/org.spongepowered.asm.mixin.transformer.MixinTransformer.transformClass(MixinTransformer.java:250)
        at MC-BOOTSTRAP/org.spongepowered.mixin/org.spongepowered.asm.service.modlauncher.MixinTransformationHandler.processClass(MixinTransformationHandler.java:131)
        at MC-BOOTSTRAP/org.spongepowered.mixin/org.spongepowered.asm.launch.MixinLaunchPluginLegacy.processClass(MixinLaunchPluginLegacy.java:131)
        at MC-BOOTSTRAP/cpw.mods.modlauncher@9.1.3/cpw.mods.modlauncher.serviceapi.ILaunchPluginService.processClassWithFlags(ILaunchPluginService.java:156)
        at MC-BOOTSTRAP/cpw.mods.modlauncher@9.1.3/cpw.mods.modlauncher.LaunchPluginHandler.offerClassNodeToPlugins(LaunchPluginHandler.java:88)
        at MC-BOOTSTRAP/cpw.mods.modlauncher@9.1.3/cpw.mods.modlauncher.ClassTransformer.transform(ClassTransformer.java:120)
        at MC-BOOTSTRAP/cpw.mods.modlauncher@9.1.3/cpw.mods.modlauncher.TransformingClassLoader.maybeTransformClassBytes(TransformingClassLoader.java:50)
        at cpw.mods.securejarhandler@1.0.3/cpw.mods.cl.ModuleClassLoader.readerToClass(ModuleClassLoader.java:110)
        at cpw.mods.securejarhandler@1.0.3/cpw.mods.cl.ModuleClassLoader.lambda$findClass$16(ModuleClassLoader.java:216)
        at cpw.mods.securejarhandler@1.0.3/cpw.mods.cl.ModuleClassLoader.loadFromModule(ModuleClassLoader.java:226)
        at cpw.mods.securejarhandler@1.0.3/cpw.mods.cl.ModuleClassLoader.findClass(ModuleClassLoader.java:216)
        at cpw.mods.securejarhandler@1.0.3/cpw.mods.cl.ModuleClassLoader.loadClass(ModuleClassLoader.java:132)
        at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:521)
        at java.base/java.lang.Class.getDeclaredMethods0(Native Method)
        at java.base/java.lang.Class.privateGetDeclaredMethods(Class.java:3458)
        at java.base/java.lang.Class.getMethodsRecursive(Class.java:3599)
        at java.base/java.lang.Class.getMethod0(Class.java:3585)
        at java.base/java.lang.Class.getMethod(Class.java:2275)
        at MC-BOOTSTRAP/fmlloader@1.18.2-40.2.0/net.minecraftforge.fml.loading.targets.CommonServerLaunchHandler.lambda$launchService$0(CommonServerLaunchHandler.java:32)
        at MC-BOOTSTRAP/cpw.mods.modlauncher@9.1.3/cpw.mods.modlauncher.LaunchServiceHandlerDecorator.launch(LaunchServiceHandlerDecorator.java:37)
        at MC-BOOTSTRAP/cpw.mods.modlauncher@9.1.3/cpw.mods.modlauncher.LaunchServiceHandler.launch(LaunchServiceHandler.java:53)
        at MC-BOOTSTRAP/cpw.mods.modlauncher@9.1.3/cpw.mods.modlauncher.LaunchServiceHandler.launch(LaunchServiceHandler.java:71)
        at MC-BOOTSTRAP/cpw.mods.modlauncher@9.1.3/cpw.mods.modlauncher.Launcher.run(Launcher.java:106)
        at MC-BOOTSTRAP/cpw.mods.modlauncher@9.1.3/cpw.mods.modlauncher.Launcher.main(Launcher.java:77)
        at MC-BOOTSTRAP/cpw.mods.modlauncher@9.1.3/cpw.mods.modlauncher.BootstrapLaunchConsumer.accept(BootstrapLaunchConsumer.java:26)
        at MC-BOOTSTRAP/cpw.mods.modlauncher@9.1.3/cpw.mods.modlauncher.BootstrapLaunchConsumer.accept(BootstrapLaunchConsumer.java:23)
        at cpw.mods.bootstraplauncher@1.0.0/cpw.mods.bootstraplauncher.BootstrapLauncher.main(BootstrapLauncher.java:149)
Caused by: org.spongepowered.asm.mixin.throwables.ClassMetadataNotFoundException: java.util.Set
        at MC-BOOTSTRAP/org.spongepowered.mixin/org.spongepowered.asm.mixin.transformer.MixinPreProcessorStandard.transformMethod(MixinPreProcessorStandard.java:754)
        at MC-BOOTSTRAP/org.spongepowered.mixin/org.spongepowered.asm.mixin.transformer.MixinPreProcessorStandard.transform(MixinPreProcessorStandard.java:739)
        at MC-BOOTSTRAP/org.spongepowered.mixin/org.spongepowered.asm.mixin.transformer.MixinPreProcessorStandard.attach(MixinPreProcessorStandard.java:310)
        at MC-BOOTSTRAP/org.spongepowered.mixin/org.spongepowered.asm.mixin.transformer.MixinPreProcessorStandard.createContextFor(MixinPreProcessorStandard.java:280)
        at MC-BOOTSTRAP/org.spongepowered.mixin/org.spongepowered.asm.mixin.transformer.MixinInfo.createContextFor(MixinInfo.java:1288)
        at MC-BOOTSTRAP/org.spongepowered.mixin/org.spongepowered.asm.mixin.transformer.MixinApplicatorStandard.apply(MixinApplicatorStandard.java:292)
        at MC-BOOTSTRAP/org.spongepowered.mixin/org.spongepowered.asm.mixin.transformer.TargetClassContext.apply(TargetClassContext.java:383)
        at MC-BOOTSTRAP/org.spongepowered.mixin/org.spongepowered.asm.mixin.transformer.TargetClassContext.applyMixins(TargetClassContext.java:365)
        at MC-BOOTSTRAP/org.spongepowered.mixin/org.spongepowered.asm.mixin.transformer.MixinProcessor.applyMixins(MixinProcessor.java:363)
        ... 27 more

E:\Everything\Minecraft\Servers\Modded SmallMC 1.18.2>pause
Press any key to continue . . .

 

Use java 17, mixin does not support java 19

Thank you!