Must-dos for getting effective support:

 

Latest: direct adfly (preferred) Mirror

 

Firstly, THIS IS A SUPPORT FORUM FOR FML/FORGE, AND ONLY FML/FORGE.  Go to a mod specific forum (whether on this site or another) to ask for help with a certain mod.

 

Secondly, search for your issue before you post (the first line of the stack trace is a good start).

When you do post your post will have possibly related topics listed above it, check those too. DO NOT REPLY to those threads.

 

 

Thirdly, if you get good help, please be sure to Thank the person by clicking on the "Thank You" link at the top-right of their post.

 

 

Lastly, BE SURE TO INCLUDE THE ENTIRE FORGEMODLOADER-CLIENT-0.LOG. Not including the log in no way helps us to help you.

 

 

Fail to comply with these rules and your thread will be locked.

 

Below is a list of things which you MUST include in your post.

 

    Read the "Common Problems and Solutions" section below.

    Include the ForgeModLoader logs and any stack trace Minecraft itself outputs on the terminal as well

    State clearly the order in which you installed any .jar mods and their versions and if you used a patcher/launcher and which one

    State what research you have already done (You should have done some, this forum is only for well-researched bugs!).

    If you mention anything about a cracked client for any reason, you get a free warning, maybe even a ban.

    Do not speak about any mod that is stupid enough to edit base files without using Forge that, as such, is incompatible with Forge.

    Use the Spoiler tag to enclose stack traces and other long information:

    Hidden

    . Do not use hidden tags, it's a nuisance.

    This is a support forum for PLAYERS, not for modders needing help with code. Modders go here: http://www.minecraftforge.net/forum/index.php/board,73.0.html

    If you are not using the latest build you will be ignored. A download link for the latest build can be found at the top of this post.

    In general give as much information as you can.  "It does not work" in no way helps us to help you and will only cause you to get in trouble. 

 

For Windows users, use this batch file to get a crash log:

http://dl.dropbox.com/u/61139081/minecrafterrortest.bat

 

Mac/Linux users can simply run your Minecraft launcher from terminal:

Code: [select]

 

java -cp minecraft.jar net.minecraft.LauncherFrame

 

 

Also be sure to:

Do NOT install ModLoader.

Do NOT use MCPatcher.

 

If you must use a launcher then use MultiMC or Magic Launcher

for modpacks use feed the beest

 

MultiMC: http://forkk.net/MultiMC4/

(not recommended) Magic Launcher: http://www.minecraftforum.net/topic/939149-launcher-magic-launcher-098-mods-options-news/

feed the beest http://feed-the-beast.com/

 

Common Problems and Solutions:

 

    java.lang.NoClassDefFoundException: net.minecraft.Launcher; Use a proper launcher. Mojang's/MultiMC/Magic Launcher are all known to work. Don't use sk89q's and mineshafter.

    java.lang.ClassNotFoundException: com/google/common/collect/MultiMap; java.lang.NoClassDefFoundError: com/google/common/io/LineProcessor; ]java.lang.RuntimeException: A download error occured: Download this: http://files.minecraftforge.net/fmllibs/fml_libs.zipand'>http://files.minecraftforge.net/fmllibs/fml_libs.zipand extract to /lib in your .minecraft folder.

(http://files.minecraftforge.net/fmllibs/fml_libs.zip) is not uptodate it is missing bcprov-jdk15on-147.jar

    java.lang.ClassNotFoundException: paulscode/sound/SoundSystem; Update forge.

    java.lang.SecurityException: SHA1 digest error for net/minecraft/client/MinecraftApplet.class; Delete META-INF. I cannot stress this enough.

    java.lang.NoSuchMethodFoundException: ModLoader.something; Update Forge. Post here if it still crashes(thanks Malvil). This is a serious ML compatibility issue.

    java.lang.UnsupportedClassVersionError: net/minecraft/client/MinecraftApplet : Unsupported major.minor version 51.0; Use Java 7. NOT 6.

    java.util.ConcurrentModificationException: Poorly written mod, or it's a bug. (thanks SanAndreasP)

    java.lang.NullPointerException with com.pclewis.mcpatcher.mod.something: For the love of god, don't use MCPatcher. Use OptiFine instead.

    If your error log does not contain net.minecraftforge.whatever or cpw.mods.fml.something, don't look to us for help. It's an issue with the mod you're using. This is as per forum rules.

    java.lang.NoClassDefFoundError: aux (for Windows users only): DO NOT extract the minecraft.jar. Some Windows bug prevents a file from being named aux.class. You'll need to get a proper archive manager (I recommend 7zip) or get a launcher or mod manager.

    java.lang.NoSuchMethodFoundException: ofCustomFonts : Install Optifine after forge. It already says so in their forum topic.

    java.lang.IllegalAccessError: tried to access field xy.z from class net.minecraftforge.something: Check your minecraft.jar to see if you have the fml_at.cfg and forge_at.cfg files. THEY ARE REQUIRED to allow FML and Forge to work.

    If you encounter a black screen, ensure BOTH your mods and coremods folders are empty.

    This version of FML is built for Minecraft a.b.c, we have detected Minecraft x.y.z in your minecraft jar file: Do as it says and get the FML/Forge versions for x.y.z.

    If MagicLauncher tells you there are errors in forge:

    Quote from: LexManos on December 02, 2012, 10:36:37 AM

 

        Dont trust MagicLaunchers BS, it lies.

 

    java.net.SocketException when connecting to a server: Ensure the client and server configs match.

    If you experience errors decompiling or get 6000+ errors in eclipse: Close eclipse, delete mcp/eclipse, replace it with mcp/forge/fml/eclipse.

    NameError: global name 'eclipse_dir' is not defined: Delete mcp/eclipse.

    There is always a log (.minecraft/ForgeModLoader-client-x.log OR ForgeModLoader-server-x.log). Please don't upload the log itself. Use spoiler tags, pastebin or http://paste.minecraftforge.net/.

    If you run into any issues, always update forge and try again before posting about it here. Often, it has been fixed in the latest forge version.

 

This may be expanded on later, make sure to read updates.

So? What do you want me to update?

java.lang.NoClassDefFoundException: net.minecraft.Launcher; Use a proper launcher. Mojang's/MultiMC/Magic Launcher are all known to work. Don't use sk89q's and mineshafter.

 

 

 

If you must use a launcher then use MultiMC or Magic Launcher

for modpacks use feed the beest

 

MultiMC: http://forkk.net/MultiMC4/

(not recommended) Magic Launcher: http://www.minecraftforum.net/topic/939149-launcher-magic-launcher-098-mods-options-news/

feed the beest http://feed-the-beast.com/