It keeps crashing but I don't know what makes it crash

[Lumino]

---- Minecraft Crash Report ----
// Don't do that.

Time: 25.03.2023, 11:31
Description: Exception in server tick loop

java.lang.NoClassDefFoundError: dev/latvian/mods/kubejs/KubeJSPlugin
    at java.lang.ClassLoader.defineClass1(Native Method) ~[?:?] {}
    at java.lang.ClassLoader.defineClass(ClassLoader.java:1012) ~[?:?] {}
    at cpw.mods.cl.ModuleClassLoader.readerToClass(ModuleClassLoader.java:116) ~[securejarhandler-1.0.3.jar:?] {}
    at cpw.mods.cl.ModuleClassLoader.lambda$findClass$16(ModuleClassLoader.java:216) ~[securejarhandler-1.0.3.jar:?] {}
    at cpw.mods.cl.ModuleClassLoader.loadFromModule(ModuleClassLoader.java:226) ~[securejarhandler-1.0.3.jar:?] {}
    at cpw.mods.cl.ModuleClassLoader.findClass(ModuleClassLoader.java:216) ~[securejarhandler-1.0.3.jar:?] {}
    at cpw.mods.cl.ModuleClassLoader.loadClass(ModuleClassLoader.java:132) ~[securejarhandler-1.0.3.jar:?] {}
    at java.lang.ClassLoader.loadClass(ClassLoader.java:520) ~[?:?] {}
    at net.impleri.playerskills.PlayerSkillsEvents.beforeServerStart(PlayerSkillsEvents.java:70) ~[player-skills-1.18.2-1.0.0.jar%2394!/:?] {re:classloading}
    at dev.architectury.event.forge.EventHandlerImplCommon.event(EventHandlerImplCommon.java:403) ~[architectury-4.11.89-forge.jar%2358!/:?] {re:classloading}
    at net.minecraftforge.eventbus.ASMEventHandler_356_EventHandlerImplCommon_event_ServerAboutToStartEvent.invoke(.dynamic) ~[?:?] {}
    at net.minecraftforge.eventbus.ASMEventHandler.invoke(ASMEventHandler.java:85) ~[eventbus-5.0.3.jar%232!/:?] {}
    at net.minecraftforge.eventbus.EventBus.post(EventBus.java:302) ~[eventbus-5.0.3.jar%232!/:?] {}
    at net.minecraftforge.eventbus.EventBus.post(EventBus.java:283) ~[eventbus-5.0.3.jar%232!/:?] {}
    at net.minecraftforge.server.ServerLifecycleHooks.handleServerAboutToStart(ServerLifecycleHooks.java:86) ~[forge-1.18.2-40.2.0-universal.jar%23124!/:?] {re:classloading}
    at net.minecraft.client.server.IntegratedServer.m_7038_(IntegratedServer.java:63) ~[client-1.18.2-20220404.173914-srg.jar%23119!/:?] {re:mixin,pl:runtimedistcleaner:A,re:classloading,pl:mixin:APP:mixins.essential.json:server.integrated.MixinIntegratedServer,pl:mixin:A,pl:runtimedistcleaner:A}
    at net.minecraft.server.MinecraftServer.m_130011_(MinecraftServer.java:661) ~[client-1.18.2-20220404.173914-srg.jar%23119!/:?] {re:mixin,pl:accesstransformer:B,re:classloading,pl:accesstransformer:B,pl:mixin:APP:balm.mixins.json:MinecraftServerMixin,pl:mixin:APP:mixins.essential.json:server.MinecraftServerMixin_PvPGameRule,pl:mixin:APP:mixins.essential.json:server.Mixin_PublishServerStatusResponse,pl:mixin:A}
    at net.minecraft.server.MinecraftServer.m_177918_(MinecraftServer.java:261) ~[client-1.18.2-20220404.173914-srg.jar%23119!/:?] {re:mixin,pl:accesstransformer:B,re:classloading,pl:accesstransformer:B,pl:mixin:APP:balm.mixins.json:MinecraftServerMixin,pl:mixin:APP:mixins.essential.json:server.MinecraftServerMixin_PvPGameRule,pl:mixin:APP:mixins.essential.json:server.Mixin_PublishServerStatusResponse,pl:mixin:A}
    at java.lang.Thread.run(Thread.java:833) [?:?] {re:mixin}
Caused by: java.lang.ClassNotFoundException: dev.latvian.mods.kubejs.KubeJSPlugin
    at jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:641) ~[?:?] {}
    at java.lang.ClassLoader.loadClass(ClassLoader.java:520) ~[?:?] {}
    at cpw.mods.cl.ModuleClassLoader.loadClass(ModuleClassLoader.java:134) ~[securejarhandler-1.0.3.jar:?] {}
    at java.lang.ClassLoader.loadClass(ClassLoader.java:520) ~[?:?] {}
    at cpw.mods.cl.ModuleClassLoader.loadClass(ModuleClassLoader.java:134) ~[securejarhandler-1.0.3.jar:?] {}
    at java.lang.ClassLoader.loadClass(ClassLoader.java:520) ~[?:?] {}
    ... 19 more
 

[warjort]

Quote

java.lang.NoClassDefFoundError: dev/latvian/mods/kubejs/KubeJSPlugin
    at java.lang.ClassLoader.defineClass1(Native Method) ~[?:?] {}
    at java.lang.ClassLoader.defineClass(ClassLoader.java:1012) ~[?:?] {}
    at cpw.mods.cl.ModuleClassLoader.readerToClass(ModuleClassLoader.java:116) ~[securejarhandler-1.0.3.jar:?] {}
    at cpw.mods.cl.ModuleClassLoader.lambda$findClass$16(ModuleClassLoader.java:216) ~[securejarhandler-1.0.3.jar:?] {}
    at cpw.mods.cl.ModuleClassLoader.loadFromModule(ModuleClassLoader.java:226) ~[securejarhandler-1.0.3.jar:?] {}
    at cpw.mods.cl.ModuleClassLoader.findClass(ModuleClassLoader.java:216) ~[securejarhandler-1.0.3.jar:?] {}
    at cpw.mods.cl.ModuleClassLoader.loadClass(ModuleClassLoader.java:132) ~[securejarhandler-1.0.3.jar:?] {}
    at java.lang.ClassLoader.loadClass(ClassLoader.java:520) ~[?:?] {}
    at net.impleri.playerskills.PlayerSkillsEvents.beforeServerStart(PlayerSkillsEvents.java:70) ~[player-skills-1.18.2-1.0.0.jar%2394!/:?] {re:classloading}

Issue with the player skills mod.

Looks like it needs the KubeJS mod installed?

[Lumino]

I installed KubeJS and it works now, thanks.