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Minecraft crash and say: Error: cpw.mods.fml.common.LoaderException:

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Posted June 22, 20214 yr

HI! I installed a map with a modpack 5 minutes ago, i put all the files in the right position, but when i open the game it crash and give me the shutdown report.

---- Minecraft Crash Report ----
// Surprise! Haha. Well, this is awkward.

Time: 22/06/21 19.54
Description: There was a severe problem during mod loading that has caused the game to fail

cpw.mods.fml.common.LoaderException: java.lang.NoClassDefFoundError: net/minecraftforge/fml/common/network/simpleimpl/IMessage
   at cpw.mods.fml.common.LoadController.transition(LoadController.java:163)
   at cpw.mods.fml.common.Loader.loadMods(Loader.java:544)
   at cpw.mods.fml.client.FMLClientHandler.beginMinecraftLoading(FMLClientHandler.java:208)
   at net.minecraft.client.Minecraft.func_71384_a(Minecraft.java:480)
   at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:878)
   at net.minecraft.client.main.Main.main(SourceFile:148)
   at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
   at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
   at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
   at java.lang.reflect.Method.invoke(Method.java:497)
   at net.minecraft.launchwrapper.Launch.launch(Launch.java:135)
   at net.minecraft.launchwrapper.Launch.main(Launch.java:28)
Caused by: java.lang.NoClassDefFoundError: net/minecraftforge/fml/common/network/simpleimpl/IMessage
   at java.lang.Class.forName0(Native Method)
   at java.lang.Class.forName(Class.java:348)
   at cpw.mods.fml.common.FMLModContainer.constructMod(FMLModContainer.java:440)
   at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
   at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
   at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
   at java.lang.reflect.Method.invoke(Method.java:497)
   at com.google.common.eventbus.EventSubscriber.handleEvent(EventSubscriber.java:74)
   at com.google.common.eventbus.SynchronizedEventSubscriber.handleEvent(SynchronizedEventSubscriber.java:47)
   at com.google.common.eventbus.EventBus.dispatch(EventBus.java:322)
   at com.google.common.eventbus.EventBus.dispatchQueuedEvents(EventBus.java:304)
   at com.google.common.eventbus.EventBus.post(EventBus.java:275)
   at cpw.mods.fml.common.LoadController.sendEventToModContainer(LoadController.java:212)
   at cpw.mods.fml.common.LoadController.propogateStateMessage(LoadController.java:190)
   at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
   at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
   at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
   at java.lang.reflect.Method.invoke(Method.java:497)
   at com.google.common.eventbus.EventSubscriber.handleEvent(EventSubscriber.java:74)
   at com.google.common.eventbus.SynchronizedEventSubscriber.handleEvent(SynchronizedEventSubscriber.java:47)
   at com.google.common.eventbus.EventBus.dispatch(EventBus.java:322)
   at com.google.common.eventbus.EventBus.dispatchQueuedEvents(EventBus.java:304)
   at com.google.common.eventbus.EventBus.post(EventBus.java:275)
   at cpw.mods.fml.common.LoadController.distributeStateMessage(LoadController.java:119)
   at cpw.mods.fml.common.Loader.loadMods(Loader.java:513)
   ... 10 more
Caused by: java.lang.ClassNotFoundException: net.minecraftforge.fml.common.network.simpleimpl.IMessage
   at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:191)
   at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
   at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
   ... 35 more
Caused by: java.lang.NullPointerException
   at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:182)
   ... 37 more

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

-- System Details --
Details:
   Minecraft Version: 1.7.10
   Operating System: Windows 10 (amd64) version 10.0
   Java Version: 1.8.0_51, Oracle Corporation
   Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
   Memory: 215593488 bytes (205 MB) / 536870912 bytes (512 MB) up to 8589934592 bytes (8192 MB)
   JVM Flags: 8 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx8G -XX:+UnlockExperimentalVMOptions -XX:+UseG1GC -XX:G1NewSizePercent=20 -XX:G1ReservePercent=20 -XX:MaxGCPauseMillis=50 -XX:G1HeapRegionSize=32M
   AABB Pool Size: 0 (0 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
   IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
   FML: MCP v9.05 FML v7.10.99.99 Minecraft Forge 10.13.4.1614 53 mods loaded, 53 mods active
   States: 'U' = Unloaded 'L' = Loaded 'C' = Constructed 'H' = Pre-initialized 'I' = Initialized 'J' = Post-initialized 'A' = Available 'D' = Disabled 'E' = Errored
   UC   mcp{9.05} [Minecraft Coder Pack] (minecraft.jar)
   UC   FML{7.10.99.99} [Forge Mod Loader] (forge-1.7.10-10.13.4.1614-1.7.10.jar)
   UC   Forge{10.13.4.1614} [Minecraft Forge] (forge-1.7.10-10.13.4.1614-1.7.10.jar)
   UC   battlegear2{1.7.10} [Mine & Blade Battlegear 2 - Bullseye] (1.7.10-MB_Battlegear2-Bullseye-1.0.8.3.jar)
   UC   bspkrsCore{6.16} [bspkrsCore] ([1.7.10]bspkrsCore-universal-6.16.jar)
   UC   StatusEffectHUD{1.27} [StatusEffectHUD] ([1.7.10]StatusEffectHUD-client-1.27.jar)
   UC   cfm{3.4.8} [§9MrCrayfish's Furniture Mod] ([Minecraft-INSIDE.com] mrcrayfishfurnituremodv3.4.81.7.10.jar)
   UC   ArchimedesShips{1.7.10 v1.7.1} [Archimedes' Ships] (ArchimedesShips-1.7.1.jar)
   UC   Backpack{2.0.1} [Backpack] (backpack-2.0.1-1.7.x.jar)
   UC   BiblioCraft{1.11.4} [BiblioCraft] (BiblioCraft[v1.11.4][MC1.7.10].jar)
   UC   BiomesOPlenty{2.1.0} [Biomes O' Plenty] (BiomesOPlenty-1.7.10-2.1.0.1889-universal.jar)
   UC   CarpentersBlocks{3.3.5} [Carpenter's Blocks] (Carpenter's Blocks v3.3.5 - MC 1.7.10.jar)
   UC   OblisgrMod{1.2.1} [OblisgrMod] (clothing.zip)
   UC   CustomSpawner{3.3.0} [DrZhark's CustomSpawner] (CustomMobSpawner 3)
   UC   customnpcs{1.7.10d} [CustomNpcs] (CustomNPCs_1.7.10d(21feb16).jar)
   UC   DamageIndicatorsMod{3.2.0} [Damage Indicators] (Damage-Indicators-Mod-1.7.10.jar)
   UE   PTRModelLib{1.0.0} [PTRModelLib] (Decocraft-2.4.2_1.7.10.jar)
   UE   props{2.4.2} [Decocraft] (Decocraft-2.4.2_1.7.10.jar)
   UC   MoCreatures{6.3.1} [DrZhark's Mo'Creatures Mod] (DrZharks MoCreatures Mod v6)
   UC   eplus{3.0.2-d} [Enchanting Plus] (EnchantingPlus-1.7.10-3.0.2-d.jar)
   UC   exoticbirds{1.0} [Exotic Birds] (Exotic Birds 1.7.10 - 1.0.3b.jar)
   UC   flansmod{4.10.0} [Flan's Mod] (Flans Mod-1.7.10-4.10.0.jar)
   UC   fossil{1.7.10 Build 7.2.1} [Fossils and Archeology Revival] (Fossils_Archeology_Revival-1.7.10_Build-7.2.1.jar)
   UC   journeymap{5.1.4p2} [JourneyMap] (journeymap-1.7.10-5.1.4p2-unlimited.jar)
   UC   lycanitesmobs{1.13.0.5 - MC 1.7.10} [Lycanites Mobs] (LycanitesMobsComplete 1.13.0.5 [1.7.10].jar)
   UC   arcticmobs{1.13.0.5 - MC 1.7.10} [Lycanites Arctic Mobs] (LycanitesMobsComplete 1.13.0.5 [1.7.10].jar)
   UC   demonmobs{1.13.0.5 - MC 1.7.10} [Lycanites Demon Mobs] (LycanitesMobsComplete 1.13.0.5 [1.7.10].jar)
   UC   desertmobs{1.13.0.5 - MC 1.7.10} [Lycanites Desert Mobs] (LycanitesMobsComplete 1.13.0.5 [1.7.10].jar)
   UC   forestmobs{1.13.0.5 - MC 1.7.10} [Lycanites Forest Mobs] (LycanitesMobsComplete 1.13.0.5 [1.7.10].jar)
   UC   freshwatermobs{1.13.0.5 - MC 1.7.10} [Lycanites Freshwater Mobs] (LycanitesMobsComplete 1.13.0.5 [1.7.10].jar)
   UC   infernomobs{1.13.0.5 - MC 1.7.10} [Lycanites Inferno Mobs] (LycanitesMobsComplete 1.13.0.5 [1.7.10].jar)
   UC   junglemobs{1.13.0.5 - MC 1.7.10} [Lycanites Jungle Mobs] (LycanitesMobsComplete 1.13.0.5 [1.7.10].jar)
   UC   mountainmobs{1.13.0.5 - MC 1.7.10} [Lycanites Mountain Mobs] (LycanitesMobsComplete 1.13.0.5 [1.7.10].jar)
   UC   plainsmobs{1.13.0.5 - MC 1.7.10} [Lycanites Plains Mobs] (LycanitesMobsComplete 1.13.0.5 [1.7.10].jar)
   UC   saltwatermobs{1.13.0.5 - MC 1.7.10} [Lycanites Saltwater Mobs] (LycanitesMobsComplete 1.13.0.5 [1.7.10].jar)
   UC   shadowmobs{1.13.0.5 - MC 1.7.10} [Lycanites Shadow Mobs] (LycanitesMobsComplete 1.13.0.5 [1.7.10].jar)
   UC   swampmobs{1.13.0.5 - MC 1.7.10} [Lycanites Swamp Mobs] (LycanitesMobsComplete 1.13.0.5 [1.7.10].jar)
   UC   MapWriter{2.1.8} [MapWriter] (MapWriter-1.7.10-2.1.10.jar)
   UC   RadixCore{2.1.1} [RadixCore] (RadixCore-1.7.10-2.1.1-universal.jar)
   UC   MCA{1.7.10-5.1.2} [Minecraft Comes Alive] (MCA-1.7.10-5.1.2-universal.jar)
   UC   mcheli{1.0.3} [MC Helicopter] (mcheli)
   UC   MiniBosses{1.2a} [Mini-Bosses] (MiniBosses-1.2a.jar)
   UC   modularpots{1.7.10.14} [Modular Flower Pots] (ModularPots-1.7.10.14-2.jar)
   UC   mw{1.11.7.7} [Modern Warfare] (mw-1.11.7.7_mc1.7.10.jar)
   UC   plantmegapack{4.33} [Plant Mega Pack] (plantmegapack-4.33-1.7.10-1492.jar)
   UC   potioncore{@VERSION@} [Potion Core] (PotionCore-1.2_beta_for_1.7.10.jar)
   UC   roadstuff{1.0.3-final} [Road Stuff] (RoadStuff-mc1.7.10-1.0.2-final.jar)
   UC   row{1.7.10-15.01.18-2} [Rails of War] (RoW-1.7.10-15.01.18-2.jar)
   UC   soundfilters{0.8_for_1.7.X} [Sound Filters] (SoundFilters-0.8_for_1.7.X.jar)
   UC   Waila{1.5.10} [Waila] (Waila-1.5.10_1.7.10.jar)
   UC   weaponmod{v1.14.3} [Balkon's WeaponMod] (weaponmod-1.14.3.jar)
   UC   witchery{0.24.1} [Witchery] (witchery-1.7.10-0.24.1.jar)
   UC   worldedit{6.1.1} [WorldEdit] (worldedit-forge-mc1.7.10-6.1.1-dist.jar)
   GL info: ' Vendor: 'NVIDIA Corporation' Version: '4.6.0 NVIDIA 457.51' Renderer: 'GeForce RTX 3070/PCIe/SSE2'

June 23, 20214 yr

1.7 is no longer supported on this forum.

Please update to a modern version of Minecraft to receive support.

This is my Forum Signature, I am currently attempting to transform it into a small guide for fixing easier issues using spoiler blocks to keep things tidy.

As the most common issue I feel I should put this outside the main bulk:

The only official source for Forge is https://files.minecraftforge.net, and the only site I trust for getting mods is CurseForge.

If you use any site other than these, please take a look at the StopModReposts project and install their browser extension, I would also advise running a virus scan.

For players asking for assistance with Forge please expand the spoiler below and read the appropriate section(s) in its/their entirety.

Spoiler

Logs (Most issues require logs to diagnose):

Spoiler

Please post logs using one of the following sites (Thank you Lumber Wizard for the list):

https://gist.github.com/: 100MB Requires member (Free)

https://pastebin.com/: 512KB as guest, 10MB as Pro ($$$)

https://hastebin.com/: 400KB

Do NOT use sites like Mediafire, Dropbox, OneDrive, Google Drive, or a site that has a countdown before offering downloads.

What to provide:

...for Crashes and Runtime issues:

Minecraft 1.14.4 and newer:

Post debug.log

Older versions:

Please update...

...for Installer Issues:

Post your installer log, found in the same place you ran the installer

This log will be called either installer.log or named the same as the installer but with .log on the end

Note for Windows users:

Windows hides file extensions by default so the installer may appear without the .jar extension then when the .log is added the log will appear with the .jar extension

Where to get it:

Mojang Launcher: When using the Mojang launcher debug.log is found in .minecraft\logs.

Curse/Overwolf: If you are using the Curse Launcher, their configurations break Forge's log settings, fortunately there is an easier workaround than I originally thought, this works even with Curse's installation of the Minecraft launcher as long as it is not launched THROUGH Twitch:

Spoiler

Make sure you have the correct version of Forge installed (some packs are heavily dependent on one specific build of Forge)
Make a launcher profile targeting this version of Forge.
Set the launcher profile's GameDir property to the pack's instance folder (not the instances folder, the folder that has the pack's name on it).
Now launch the pack through that profile and follow the "Mojang Launcher" instructions above.

Video:

Spoiler

or alternately,

Fallback ("No logs are generated"):

If you don't see logs generated in the usual place, provide the launcher_log.txt from .minecraft

Server Not Starting:

Spoiler

If your server does not start or a command window appears and immediately goes away, run the jar manually and provide the output.

Reporting Illegal/Inappropriate Adfocus Ads:

Spoiler

Get a screenshot of the URL bar or copy/paste the whole URL into a thread on the General Discussion board with a description of the Ad.

Lex will need the Ad ID contained in that URL to report it to Adfocus' support team.

Posting your mod as a GitHub Repo:

Spoiler

When you have an issue with your mod the most helpful thing you can do when asking for help is to provide your code to those helping you. The most convenient way to do this is via GitHub or another source control hub.

When setting up a GitHub Repo it might seem easy to just upload everything, however this method has the potential for mistakes that could lead to trouble later on, it is recommended to use a Git client or to get comfortable with the Git command line. The following instructions will use the Git Command Line and as such they assume you already have it installed and that you have created a repository.

Open a command prompt (CMD, Powershell, Terminal, etc).
Navigate to the folder you extracted Forge’s MDK to (the one that had all the licenses in).
Run the following commands:
1. git init
2. git remote add origin [Your Repository's URL]
  - In the case of GitHub it should look like: https://GitHub.com/[Your Username]/[Repo Name].git
3. git fetch
4. git checkout --track origin/master
5. git stage *
6. git commit -m "[Your commit message]"
7. git push
Navigate to GitHub and you should now see most of the files.
- note that it is intentional that some are not synced with GitHub and this is done with the (hidden) .gitignore file that Forge’s MDK has provided (hence the strictness on which folder git init is run from)
Now you can share your GitHub link with those who you are asking for help.

[Workaround line, please ignore]

This topic is now closed to further replies.

https://forums.minecraftforge.net/topic/101646-minecraft-crash-and-say-error-cpwmodsfmlcommonloaderexception/

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Minecraft crash and say: Error: cpw.mods.fml.common.LoaderException:

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