Hello there, i want to ask someone, if there will be server pack updated to the newest version of MC Eternal...?
Currently i have problems with even starting the server....

[11:51:24] [Server thread/ERROR] [minecraft/MinecraftServer]: Encountered an unexpected exception java.lang.NoClassDefFoundError: net/minecraft/client/gui/GuiScreen at java.lang.Class.forName0(Native Method) ~[?:1.8.0_312] at java.lang.Class.forName(Class.java:348) ~[?:1.8.0_312] at net.minecraftforge.fml.common.FMLModContainer.constructMod(FMLModContainer.java:539) ~[server.jar:?] at sun.reflect.GeneratedMethodAccessor11.invoke(Unknown Source) ~[?:?] at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_312] at java.lang.reflect.Method.invoke(Method.java:498) ~[?:1.8.0_312] 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$PerThreadQueuedDispatcher.dispatch(Dispatcher.java:116) ~[minecraft_server.1.12.2.jar:?] at com.google.common.eventbus.EventBus.post(EventBus.java:217) ~[minecraft_server.1.12.2.jar:?] at net.minecraftforge.fml.common.LoadController.sendEventToModContainer(LoadController.java:219) ~[LoadController.class:?] at net.minecraftforge.fml.common.LoadController.propogateStateMessage(LoadController.java:197) ~[LoadController.class:?] at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_312] at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_312] at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_312] at java.lang.reflect.Method.invoke(Method.java:498) ~[?:1.8.0_312] at com.google.common.eventbus.Subscriber.invokeSubscriberMethod(Subscriber.java:91) ~[minecraft_server.1.12.2.jar:?] at com.google.common.eventbus.Subscriber$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$PerThreadQueuedDispatcher.dispatch(Dispatcher.java:116) ~[minecraft_server.1.12.2.jar:?] at com.google.common.eventbus.EventBus.post(EventBus.java:217) ~[minecraft_server.1.12.2.jar:?] at net.minecraftforge.fml.common.LoadController.distributeStateMessage(LoadController.java:136) ~[LoadController.class:?] at net.minecraftforge.fml.common.Loader.loadMods(Loader.java:595) ~[Loader.class:?] at net.minecraftforge.fml.server.FMLServerHandler.beginServerLoading(FMLServerHandler.java:98) ~[FMLServerHandler.class:?] at net.minecraftforge.fml.common.FMLCommonHandler.onServerStart(FMLCommonHandler.java:333) ~[FMLCommonHandler.class:?] at net.minecraft.server.dedicated.DedicatedServer.init(DedicatedServer.java:125) ~[nz.class:?] at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:486) [MinecraftServer.class:?] at java.lang.Thread.run(Thread.java:748) [?:1.8.0_312] Caused by: java.lang.ClassNotFoundException: net.minecraft.client.gui.GuiScreen at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:191) ~[launchwrapper-1.12.jar:?] at java.lang.ClassLoader.loadClass(ClassLoader.java:418) ~[?:1.8.0_312] at java.lang.ClassLoader.loadClass(ClassLoader.java:351) ~[?:1.8.0_312] ... 33 more Caused by: net.minecraftforge.fml.common.asm.ASMTransformerWrapper$TransformerException: Exception in class transformer net.minecraftforge.fml.common.asm.transformers.SideTransformer@71a06021 from coremod FMLCorePlugin at net.minecraftforge.fml.common.asm.ASMTransformerWrapper$TransformerWrapper.transform(ASMTransformerWrapper.java:260) ~[server.jar:?] at net.minecraft.launchwrapper.LaunchClassLoader.runTransformers(LaunchClassLoader.java:279) ~[launchwrapper-1.12.jar:?] at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:176) ~[launchwrapper-1.12.jar:?] at java.lang.ClassLoader.loadClass(ClassLoader.java:418) ~[?:1.8.0_312] at java.lang.ClassLoader.loadClass(ClassLoader.java:351) ~[?:1.8.0_312] ... 33 more Caused by: java.lang.RuntimeException: Attempted to load class blk for invalid side SERVER at net.minecraftforge.fml.common.asm.transformers.SideTransformer.transform(SideTransformer.java:62) ~[server.jar:?] at net.minecraftforge.fml.common.asm.ASMTransformerWrapper$TransformerWrapper.transform(ASMTransformerWrapper.java:256) ~[server.jar:?] at net.minecraft.launchwrapper.LaunchClassLoader.runTransformers(LaunchClassLoader.java:279) ~[launchwrapper-1.12.jar:?] at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:176) ~[launchwrapper-1.12.jar:?] at java.lang.ClassLoader.loadClass(ClassLoader.java:418) ~[?:1.8.0_312] at java.lang.ClassLoader.loadClass(ClassLoader.java:351) ~[?:1.8.0_312] ... 33 more [11:51:24] [Server thread/WARN] [enderio]: @Devs: See github for dev env setup; set INDEV if needed. [11:51:24] [Server thread/WARN] [org.dimdev.utils.ModIdentifier]: Failed to identify sun.reflect.GeneratedMethodAccessor11 (untransformed name: sun.reflect.GeneratedMethodAccessor11) [11:51:24] [Server thread/ERROR] [minecraft/MinecraftServer]: This crash report has been saved to: /home/container/./crash-reports/crash-2023-12-16_11.51.24-server.txt [11:51:24] [Server thread/INFO] [minecraft/MinecraftServer]: Stopping server [11:51:24] [Server thread/INFO] [minecraft/MinecraftServer]: Saving worlds Exception in thread "Server thread" [11:51:24] [Server thread/INFO] [STDERR]: [java.lang.ThreadGroup:uncaughtException:1061]: net.minecraftforge.fml.common.LoaderExceptionModCrash: Caught exception from Advanced Rocketry (advancedrocketry) [11:51:24] [Server thread/INFO] [STDERR]: [net.minecraftforge.fml.common.EnhancedRuntimeException:printStackTrace:92]: Caused by: java.lang.NullPointerException [11:51:24] [Server thread/INFO] [STDERR]: [net.minecraftforge.fml.common.EnhancedRuntimeException:printStackTrace:92]: at zmaster587.advancedRocketry.cable.NetworkRegistry.clearNetworks(NetworkRegistry.java:16) [11:51:24] [Server thread/INFO] [STDERR]: [net.minecraftforge.fml.common.EnhancedRuntimeException:printStackTrace:92]: at zmaster587.advancedRocketry.AdvancedRocketry.serverStopped(AdvancedRocketry.java:1237) [11:51:24] [Server thread/INFO] [STDERR]: [net.minecraftforge.fml.common.EnhancedRuntimeException:printStackTrace:92]: at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) [11:51:24] [Server thread/INFO] [STDERR]: [net.minecraftforge.fml.common.EnhancedRuntimeException:printStackTrace:92]: at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) [11:51:24] [Server thread/INFO] [STDERR]: [net.minecraftforge.fml.common.EnhancedRuntimeException:printStackTrace:92]: at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) [11:51:24] [Server thread/INFO] [STDERR]: [net.minecraftforge.fml.common.EnhancedRuntimeException:printStackTrace:92]: at java.lang.reflect.Method.invoke(Method.java:498) [11:51:24] [Server thread/INFO] [STDERR]: [net.minecraftforge.fml.common.EnhancedRuntimeException:printStackTrace:92]: at net.minecraftforge.fml.common.FMLModContainer.handleModStateEvent(FMLModContainer.java:637) [11:51:24] [Server thread/INFO] [STDERR]: [net.minecraftforge.fml.common.EnhancedRuntimeException:printStackTrace:92]: at sun.reflect.GeneratedMethodAccessor10.invoke(Unknown Source) [11:51:24] [Server thread/INFO] [STDERR]: [net.minecraftforge.fml.common.EnhancedRuntimeException:printStackTrace:92]: at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) [11:51:24] [Server thread/INFO] [STDERR]: [net.minecraftforge.fml.common.EnhancedRuntimeException:printStackTrace:92]: at java.lang.reflect.Method.invoke(Method.java:498) [11:51:24] [Server thread/INFO] [STDERR]: [net.minecraftforge.fml.common.EnhancedRuntimeException:printStackTrace:92]: at com.google.common.eventbus.Subscriber.invokeSubscriberMethod(Subscriber.java:91) [11:51:24] [Server thread/INFO] [STDERR]: [net.minecraftforge.fml.common.EnhancedRuntimeException:printStackTrace:92]: at com.google.common.eventbus.Subscriber$SynchronizedSubscriber.invokeSubscriberMethod(Subscriber.java:150) [11:51:24] [Server thread/INFO] [STDERR]: [net.minecraftforge.fml.common.EnhancedRuntimeException:printStackTrace:92]: at com.google.common.eventbus.Subscriber$1.run(Subscriber.java:76) [11:51:24] [Server thread/INFO] [STDERR]: [net.minecraftforge.fml.common.EnhancedRuntimeException:printStackTrace:92]: at com.google.common.util.concurrent.MoreExecutors$DirectExecutor.execute(MoreExecutors.java:399) [11:51:24] [Server thread/INFO] [STDERR]: [net.minecraftforge.fml.common.EnhancedRuntimeException:printStackTrace:92]: at com.google.common.eventbus.Subscriber.dispatchEvent(Subscriber.java:71) [11:51:24] [Server thread/INFO] [STDERR]: [net.minecraftforge.fml.common.EnhancedRuntimeException:printStackTrace:92]: at com.google.common.eventbus.Dispatcher$PerThreadQueuedDispatcher.dispatch(Dispatcher.java:116) [11:51:24] [Server thread/INFO] [STDERR]: [net.minecraftforge.fml.common.EnhancedRuntimeException:printStackTrace:92]: at com.google.common.eventbus.EventBus.post(EventBus.java:217) [11:51:24] [Server thread/INFO] [STDERR]: [net.minecraftforge.fml.common.EnhancedRuntimeException:printStackTrace:92]: at net.minecraftforge.fml.common.LoadController.sendEventToModContainer(LoadController.java:219) [11:51:24] [Server thread/INFO] [STDERR]: [net.minecraftforge.fml.common.EnhancedRuntimeException:printStackTrace:92]: at net.minecraftforge.fml.common.LoadController.propogateStateMessage(LoadController.java:197) [11:51:24] [Server thread/INFO] [STDERR]: [net.minecraftforge.fml.common.EnhancedRuntimeException:printStackTrace:92]: at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) [11:51:24] [Server thread/INFO] [STDERR]: [net.minecraftforge.fml.common.EnhancedRuntimeException:printStackTrace:92]: at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) [11:51:24] [Server thread/INFO] [STDERR]: [net.minecraftforge.fml.common.EnhancedRuntimeException:printStackTrace:92]: at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) [11:51:24] [Server thread/INFO] [STDERR]: [net.minecraftforge.fml.common.EnhancedRuntimeException:printStackTrace:92]: at java.lang.reflect.Method.invoke(Method.java:498) [11:51:24] [Server thread/INFO] [STDERR]: [net.minecraftforge.fml.common.EnhancedRuntimeException:printStackTrace:92]: at com.google.common.eventbus.Subscriber.invokeSubscriberMethod(Subscriber.java:91) [11:51:24] [Server thread/INFO] [STDERR]: [net.minecraftforge.fml.common.EnhancedRuntimeException:printStackTrace:92]: at com.google.common.eventbus.Subscriber$SynchronizedSubscriber.invokeSubscriberMethod(Subscriber.java:150) [11:51:24] [Server thread/INFO] [STDERR]: [net.minecraftforge.fml.common.EnhancedRuntimeException:printStackTrace:92]: at com.google.common.eventbus.Subscriber$1.run(Subscriber.java:76) [11:51:24] [Server thread/INFO] [STDERR]: [net.minecraftforge.fml.common.EnhancedRuntimeException:printStackTrace:92]: at com.google.common.util.concurrent.MoreExecutors$DirectExecutor.execute(MoreExecutors.java:399) [11:51:24] [Server thread/INFO] [STDERR]: [net.minecraftforge.fml.common.EnhancedRuntimeException:printStackTrace:92]: at com.google.common.eventbus.Subscriber.dispatchEvent(Subscriber.java:71) [11:51:24] [Server thread/INFO] [STDERR]: [net.minecraftforge.fml.common.EnhancedRuntimeException:printStackTrace:92]: at com.google.common.eventbus.Dispatcher$PerThreadQueuedDispatcher.dispatch(Dispatcher.java:116) [11:51:24] [Server thread/INFO] [STDERR]: [net.minecraftforge.fml.common.EnhancedRuntimeException:printStackTrace:92]: at com.google.common.eventbus.EventBus.post(EventBus.java:217) [11:51:24] [Server thread/INFO] [STDERR]: [net.minecraftforge.fml.common.EnhancedRuntimeException:printStackTrace:92]: at net.minecraftforge.fml.common.LoadController.distributeStateMessage(LoadController.java:136) [11:51:24] [Server thread/INFO] [STDERR]: [net.minecraftforge.fml.common.EnhancedRuntimeException:printStackTrace:92]: at net.minecraftforge.fml.common.Loader.serverStopped(Loader.java:852) [11:51:24] [Server thread/INFO] [STDERR]: [net.minecraftforge.fml.common.EnhancedRuntimeException:printStackTrace:92]: at net.minecraftforge.fml.common.FMLCommonHandler.handleServerStopped(FMLCommonHandler.java:508) [11:51:24] [Server thread/INFO] [STDERR]: [net.minecraftforge.fml.common.EnhancedRuntimeException:printStackTrace:92]: at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:587) [11:51:24] [Server thread/INFO] [STDERR]: [net.minecraftforge.fml.common.EnhancedRuntimeException:printStackTrace:92]: at java.lang.Thread.run(Thread.java:748)

there is a server pack that is under review by curseforge as i write this very comment, so yes.
your particular issue is likely not removing the packmodemenu mod.
waiting for the server pack is recommended, and it should be available within the next few days, no doubt there.

additionally, if you experience any more crashes that are causing trouble, it's recommended you come to the MCE discord, you'll get a far quicker response there.