This is just a small tutorial i wrote. I might extend this later, though.
1. Don't Panic.
Just like in any emergency: Keep calm. Only a small percentage of all crashes cannot be fixed by a few tweaks.
2. Check for common mistakes.
Check if you made one of these:
- you used mods that don't fit your minecraft version, e.g. a 1.8 mod in 1.7.10 minecraft.
- you tried to play minecraft offline without downloading it before (unlikely if you already installed forge).
2. Search for your Crashlog.
It can be found in <MINECRAFTFOLDER>/logs. Note that <MINECRAFTFOLDER> is different from launcher to launcher (default on windows: C:\\<USERNAME>\AppData\.minecraft ). But most launchers have an "open instance folder" button or something similiar.
Now you got your crashlog. If this is you first time looking at something like this, it might scare you. So many cryptic lines...
If you want to try it, here's a small guide on how to read crashlogs. Just to point this out, this one is horribly incomplete. if you want a good tutorial for crashlogs, better have a look at Robijnvogel’s general guide to modded Minecraft crash troubleshooting
first of all, you want to find the stacktrace. it usually looks like this:
cpw.mods.fml.common.LoaderException: java.lang.NoClassDefFoundError: mods/castledef/azurn/EntityKnight
at cpw.mods.fml.common.LoadController.transition(LoadController.java:142)
at cpw.mods.fml.common.Loader.initializeMods(Loader.java:690)
at cpw.mods.fml.client.FMLClientHandler.finishMinecraftLoading(FMLClientHandler.java:206)
at net.minecraft.client.Minecraft.func_71384_a(Minecraft.java:444)
at net.minecraft.client.MinecraftAppletImpl.func_71384_a(SourceFile:56)
at net.minecraft.client.Minecraft.run(Minecraft.java:729)
at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.NoClassDefFoundError: mods/castledef/azurn/EntityKnight
at mods.castledef.client.ClientProxyCastleDef.registerRenderThings(ClientProxyCastleDef.java:20)
at mods.castledef.azurn.mod_castledef.load(mod_castledef.java:116)
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 cpw.mods.fml.common.FMLModContainer.handleModStateEvent(FMLModContainer.java:515)
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.EventHandler.handleEvent(EventHandler.java:74)
at com.google.common.eventbus.SynchronizedEventHandler.handleEvent(SynchronizedEventHandler.java:45)
at com.google.common.eventbus.EventBus.dispatch(EventBus.java:314)
at com.google.common.eventbus.EventBus.dispatchQueuedEvents(EventBus.java:296)
at com.google.common.eventbus.EventBus.post(EventBus.java:267)
at cpw.mods.fml.common.LoadController.propogateStateMessage(LoadController.java:165)
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.EventHandler.handleEvent(EventHandler.java:74)
at com.google.common.eventbus.SynchronizedEventHandler.handleEvent(SynchronizedEventHandler.java:45)
at com.google.common.eventbus.EventBus.dispatch(EventBus.java:314)
at com.google.common.eventbus.EventBus.dispatchQueuedEvents(EventBus.java:296)
at com.google.common.eventbus.EventBus.post(EventBus.java:267)
at cpw.mods.fml.common.LoadController.distributeStateMessage(LoadController.java:98)
at cpw.mods.fml.common.Loader.initializeMods(Loader.java:689)
you can find it by simply looking for a huge amount of lines that start with "at". now all you have to is look at the exception. here is a list of common exceptions. In this case it's a "NoClassDefFoundError", which appears when you try to load a wrong version mod.
But which mod is it that fails to load?
Have a closer look at your stacktrace. most lines contain something like "cpw.mods.fml.", "sun.", net.minecraft." or "com.google.". This is just the game mechanic. So what lines are unusal here? The one starting with "mods.castledef". and this is it, it's the signature of the failing mod. The standart signature notation goes like this: [prefix].[author].[modID] - note that the prefix is not always used. as an example, the signature of my mod SimpleLeather is com.mcofficer.simpleleather.
Now you know which mod is causing the crash. if you can live without it, simply remove it. otherwise, try to find the cause. updating to a newer version is always recommended and fixes a lot of crashes occuring in older modpacks. otherwise, search for the mod's issue tracker (normally located on their curseforge or github page) and search for an error like yours. make sure the stacktraces are truly similiar before posting a "i have this crash, too". if you cant find anything similiar, proceed to step 3.
3. Ask at minecraftforum.net
You tried it yourself, now you ask others for help. First of all, read this post: How To Ask For Help
It will carry you through most of the process. Trust me, the more info you provide, the faster you will have a fix. Remember, this is not a chatroom, so the more info we have to request, the longer it will take. Or, simply put: don't be a jerk.
5. After the Fix
So someone fixed it for you? Glad to hear that, but before diving into the pleasures of minecraft again: thank them!
most supporters are active in a bunch of posts at once, which results in pretty impressive views like this:
so these guys are literally sacrificing their time to help you with your crashes. just post a nice "thank you :)" and/or hit the thanks-button, along with the note that it's fixed.
And there's one more thing to do: tag your thread as "resolved" or "fixed".
and that's it! i hope it wasn't too useless thanks for reading!
You tried it yourself, now you ask others for help. First of all, read this post: How To Ask For Help
It will carry you through most of the process. Trust me, the more info you provide, the faster you will have a fix. Remember, this is not a chatroom, so the more info we have to request, the longer it will take. Or, simply put: don't be a jerk.
create your own thread with all the necessary information, please. if you want me to have a look at it, leave a link to it here.
This is just a small tutorial i wrote. I might extend this later, though.
1. Don't Panic.
Just like in any emergency: Keep calm. Only a small percentage of all crashes cannot be fixed by a few tweaks.
2. Check for common mistakes.
Check if you made one of these:
- you used mods that don't fit your minecraft version, e.g. a 1.8 mod in 1.7.10 minecraft.
- you tried to play minecraft offline without downloading it before (unlikely if you already installed forge).
2. Search for your Crashlog.
It can be found in <MINECRAFTFOLDER>/logs. Note that <MINECRAFTFOLDER> is different from launcher to launcher (default on windows: C:\\<USERNAME>\AppData\.minecraft ). But most launchers have an "open instance folder" button or something similiar.
Now you got your crashlog. If this is you first time looking at something like this, it might scare you. So many cryptic lines...
If you want to try it, here's a small guide on how to read crashlogs. Just to point this out, this one is horribly incomplete. if you want a good tutorial for crashlogs, better have a look at Robijnvogel’s general guide to modded Minecraft crash troubleshooting
you can find it by simply looking for a huge amount of lines that start with "at". now all you have to is look at the exception. here is a list of common exceptions. In this case it's a "NoClassDefFoundError", which appears when you try to load a wrong version mod.
But which mod is it that fails to load?
Have a closer look at your stacktrace. most lines contain something like "cpw.mods.fml.", "sun.", net.minecraft." or "com.google.". This is just the game mechanic. So what lines are unusal here? The one starting with "mods.castledef". and this is it, it's the signature of the failing mod. The standart signature notation goes like this: [prefix].[author].[modID] - note that the prefix is not always used. as an example, the signature of my mod SimpleLeather is com.mcofficer.simpleleather.
Now you know which mod is causing the crash. if you can live without it, simply remove it. otherwise, try to find the cause. updating to a newer version is always recommended and fixes a lot of crashes occuring in older modpacks. otherwise, search for the mod's issue tracker (normally located on their curseforge or github page) and search for an error like yours. make sure the stacktraces are truly similiar before posting a "i have this crash, too". if you cant find anything similiar, proceed to step 3.
3. Ask at minecraftforum.net
You tried it yourself, now you ask others for help. First of all, read this post: How To Ask For Help
It will carry you through most of the process. Trust me, the more info you provide, the faster you will have a fix. Remember, this is not a chatroom, so the more info we have to request, the longer it will take. Or, simply put: don't be a jerk.
5. After the Fix
So someone fixed it for you? Glad to hear that, but before diving into the pleasures of minecraft again: thank them!
most supporters are active in a bunch of posts at once, which results in pretty impressive views like this:
so these guys are literally sacrificing their time to help you with your crashes. just post a nice "thank you :)" and/or hit the thanks-button, along with the note that it's fixed.
And there's one more thing to do: tag your thread as "resolved" or "fixed".
and that's it! i hope it wasn't too useless thanks for reading!
create your own thread with all the necessary information, please. if you want me to have a look at it, leave a link to it here.