hi! i just created a minecraft server using forge, and it runs normally.

 

but, i try to start it again with just one mod, it crashes immidiately. 

i am running the server with 6gb of ram, it's 1.12.2 and i would like to run Decocraft mod, Worldedit mod, Securitycraft mod.

 

i'll provide crash log right here. 

 

---- Minecraft Crash Report ----

WARNING: coremods are present:
  SpongeCoremod (spongeforge-1.12.2-2838-7.3.0.jar)
Contact their authors BEFORE contacting forge

// My bad.

Time: 19/01/21 8.43
Description: Exception in server tick loop

java.lang.NoClassDefFoundError: com/mia/craftstudio/IPackReaderCallback
    at java.lang.Class.forName0(Native Method)
    at java.lang.Class.forName(Unknown Source)
    at net.minecraftforge.fml.common.FMLModContainer.constructMod(FMLModContainer.java:539)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at com.google.common.eventbus.Subscriber.invokeSubscriberMethod(Subscriber.java:91)
    at com.google.common.eventbus.Subscriber$SynchronizedSubscriber.invokeSubscriberMethod(Subscriber.java:150)
    at com.google.common.eventbus.Subscriber$1.run(Subscriber.java:76)
    at com.google.common.util.concurrent.MoreExecutors$DirectExecutor.execute(MoreExecutors.java:399)
    at com.google.common.eventbus.Subscriber.dispatchEvent(Subscriber.java:71)
    at com.google.common.eventbus.Dispatcher$PerThreadQueuedDispatcher.dispatch(Dispatcher.java:116)
    at com.google.common.eventbus.EventBus.post(EventBus.java:217)
    at net.minecraftforge.fml.common.LoadController.sendEventToModContainer(LoadController.java:219)
    at net.minecraftforge.fml.common.LoadController.propogateStateMessage(LoadController.java:197)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at com.google.common.eventbus.Subscriber.invokeSubscriberMethod(Subscriber.java:91)
    at com.google.common.eventbus.Subscriber$SynchronizedSubscriber.invokeSubscriberMethod(Subscriber.java:150)
    at com.google.common.eventbus.Subscriber$1.run(Subscriber.java:76)
    at com.google.common.util.concurrent.MoreExecutors$DirectExecutor.execute(MoreExecutors.java:399)
    at com.google.common.eventbus.Subscriber.dispatchEvent(Subscriber.java:71)
    at com.google.common.eventbus.Dispatcher$PerThreadQueuedDispatcher.dispatch(Dispatcher.java:116)
    at com.google.common.eventbus.EventBus.post(EventBus.java:217)
    at net.minecraftforge.fml.common.LoadController.redirect$zza000$forgeImpl$PostEvent(LoadController.java:568)
    at net.minecraftforge.fml.common.LoadController.distributeStateMessage(LoadController.java:136)
    at net.minecraftforge.fml.common.Loader.loadMods(Loader.java:595)
    at net.minecraftforge.fml.server.FMLServerHandler.beginServerLoading(FMLServerHandler.java:98)
    at net.minecraftforge.fml.common.FMLCommonHandler.onServerStart(FMLCommonHandler.java:333)
    at net.minecraft.server.dedicated.DedicatedServer.func_71197_b(DedicatedServer.java:125)
    at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:486)
    at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.ClassNotFoundException: com.mia.craftstudio.IPackReaderCallback
    at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:191)
    at java.lang.ClassLoader.loadClass(Unknown Source)
    at java.lang.ClassLoader.loadClass(Unknown Source)
    ... 35 more
Caused by: java.lang.NullPointerException

A detailed walkthrough of the error, its code path and all known details is as follows:
---------------------------------------------------------------------------------------

-- Head --
Thread: Server thread
Stacktrace:
    at java.lang.Class.forName0(Native Method)
    at java.lang.Class.forName(Unknown Source)
    at net.minecraftforge.fml.common.FMLModContainer.constructMod(FMLModContainer.java:539)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at com.google.common.eventbus.Subscriber.invokeSubscriberMethod(Subscriber.java:91)
    at com.google.common.eventbus.Subscriber$SynchronizedSubscriber.invokeSubscriberMethod(Subscriber.java:150)
    at com.google.common.eventbus.Subscriber$1.run(Subscriber.java:76)
    at com.google.common.util.concurrent.MoreExecutors$DirectExecutor.execute(MoreExecutors.java:399)
    at com.google.common.eventbus.Subscriber.dispatchEvent(Subscriber.java:71)
    at com.google.common.eventbus.Dispatcher$PerThreadQueuedDispatcher.dispatch(Dispatcher.java:116)
    at com.google.common.eventbus.EventBus.post(EventBus.java:217)
    at net.minecraftforge.fml.common.LoadController.sendEventToModContainer(LoadController.java:219)
    at net.minecraftforge.fml.common.LoadController.propogateStateMessage(LoadController.java:197)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at com.google.common.eventbus.Subscriber.invokeSubscriberMethod(Subscriber.java:91)
    at com.google.common.eventbus.Subscriber$SynchronizedSubscriber.invokeSubscriberMethod(Subscriber.java:150)
    at com.google.common.eventbus.Subscriber$1.run(Subscriber.java:76)
    at com.google.common.util.concurrent.MoreExecutors$DirectExecutor.execute(MoreExecutors.java:399)
    at com.google.common.eventbus.Subscriber.dispatchEvent(Subscriber.java:71)
    at com.google.common.eventbus.Dispatcher$PerThreadQueuedDispatcher.dispatch(Dispatcher.java:116)
    at com.google.common.eventbus.EventBus.post(EventBus.java:217)
    at net.minecraftforge.fml.common.LoadController.redirect$zza000$forgeImpl$PostEvent(LoadController.java:568)
    at net.minecraftforge.fml.common.LoadController.distributeStateMessage(LoadController.java:136)
    at net.minecraftforge.fml.common.Loader.loadMods(Loader.java:595)

-- Sponge PhaseTracker --
Details:
    Phase Stack: [Empty stack]
Stacktrace:
    at net.minecraft.server.MinecraftServer.handler$zjg000$onCrashReport(MinecraftServer.java:4687)
    at net.minecraft.server.MinecraftServer.func_71230_b(MinecraftServer.java:889)
    at net.minecraft.server.dedicated.DedicatedServer.func_71230_b(DedicatedServer.java:371)
    at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:558)
    at java.lang.Thread.run(Unknown Source)

-- System Details --
Details:
    Minecraft Version: 1.12.2
    Operating System: Windows 10 (amd64) version 10.0
    Java Version: 1.8.0_271, Oracle Corporation
    Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
    Memory: 5301218152 bytes (5055 MB) / 6228017152 bytes (5939 MB) up to 6228017152 bytes (5939 MB)
    JVM Flags: 2 total; -Xms6G -Xmx6G
    IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
    FML: MCP 9.42 Powered by Forge 14.23.5.2854 8 mods loaded, 8 mods active
    States: 'U' = Unloaded 'L' = Loaded 'C' = Constructed 'H' = Pre-initialized 'I' = Initialized 'J' = Post-initialized 'A' = Available 'D' = Disabled 'E' = Errored

    Mods:

    | State | ID          | Version           | Source                            | Signature                                |
    |:----- |:----------- |:----------------- |:--------------------------------- |:---------------------------------------- |
    | LC    | minecraft   | 1.12.2            | minecraft.jar                     | None                                     |
    | LC    | mcp         | 9.42              | minecraft.jar                     | None                                     |
    | LC    | FML         | 8.0.99.99         | server.jar                        | e3c3d50c7c986df74c645c0ac54639741c90a557 |
    | LC    | forge       | 14.23.5.2854      | server.jar                        | e3c3d50c7c986df74c645c0ac54639741c90a557 |
    | LC    | spongeapi   | 7.3-7127e0882     | spongeforge-1.12.2-2838-7.3.0.jar | None                                     |
    | LC    | sponge      | 1.12.2-7.3.0      | spongeforge-1.12.2-2838-7.3.0.jar | None                                     |
    | LC    | spongeforge | 1.12.2-2838-7.3.0 | spongeforge-1.12.2-2838-7.3.0.jar | None                                     |
    | L     | props       | 2.6.3             | Decocraft-2.6.3_1.12.2.jar        | None                                     |

    Plugins:

    | State | ID | Version | Source | Signature |
    |:----- |:-- |:------- |:------ |:--------- |

    Loaded coremods (and transformers): 
SpongeCoremod (spongeforge-1.12.2-2838-7.3.0.jar)
  org.spongepowered.common.launch.transformer.SpongeSuperclassTransformer
    Profiler Position: N/A (disabled)
    Is Modded: Definitely; Server brand changed to 'fml,forge,sponge'
    Type: Dedicated Server (map_server.txt)

1.12.2 is no longer supported on this forum.

Please upgrade to a modern version to receive support.