How To Read Minecraft Crash Reports

Overview

When modifying a server, you may encounter issues with the server crashing. These crashes are typically caused by mods, the world, or the server jar. When a server crashes, it generates a crash report in the server files.

These crash reports provide a breakdown of why the server crashed and can help you understand what went wrong and how to fix it. While they may seem confusing at first, all crash reports are similar, and once you know what to look for, you’ll be able to accurately read Minecraft crash reports.

Understanding a Crash Report

Where to Find the Crash Reports

1. Head to your server’s Web Interface and on the left side of the page, click File Browser under TOOLS.
2. Once in the File Browser, open your Minecraft server folder. Inside, you will find a folder named crash-reports. Open it to view the crash reports.
3. Each file is named with the date (e.g., 2019-08-17), making it easy to identify when each report was generated. If there are multiple files, it’s best to look at the most recent one to identify the issue.
4. To read a crash report, click on the file name to open it in the editing view.

Reading the Crash Report

The top portion of the report includes the date, time, and stack trace. The stack trace shows a report of the program’s execution at a specific time. This is where you’ll primarily find the error causing the server or client to crash.

 ---- Minecraft Crash Report ----
 // Everything's going to plan. No, really, that was supposed to happen.

 Time: 1/24/20 7:25 AM
 Description: Exception in server tick loop

 Missing Mods: unknown : need [1.5.2,): have

 missing net.minecraftforge.fml.common.MissingModsException: Mod thaumcraft (Thaumcraft) requires 
 [email protected] [1.5.2,)] 
 at net.minecraftforge.fml.common.Loader.sortModList(Loader.java:266) 
 at net.minecraftforge.fml.common.Loader.loadMods(Loader.java:572) 
 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(Thread.java:748)

In this example, the error indicates that a mod is missing. The stack trace mentions “Missing Mods: unknown : need [1.5.2,): have missing“. Further down, it specifies “net.minecraftforge.fml.common.MissingModsException: Mod thaumcraft (Thaumcraft) requires [email protected] [1.5.2,)]“, meaning that the mod Thaumcraft needs the mod Baubles version 1.5.2 to function properly.

System Details and Mod States

The second half of the crash report details your system’s specifications and the states of the mods during loading. This information includes the Java version, allocated RAM, and mod versions, which can assist in troubleshooting.

One of the key tools in crash reports is understanding the states in which a mod loads. These states are:

• ‘U’ = Unloaded
• ‘L’ = Loaded
• ‘C’ = Constructed
• ‘H’ = Pre-initialized
• ‘I’ = Initialized
• ‘J’ = Post-initialized
• ‘A’ = Available
• ‘D’ = Disabled
• ‘E’ = Errored

You can see these states to the left of each mod in the report. For example, if a mod’s state is ‘UCE’, it means the mod was Unloaded, Constructed, and then Errored, which helps you identify the mod causing the issue and investigate further.

Conclusion

There are numerous reasons why your server might crash, including issues with the world, server jar, mods, and more. By narrowing down the cause, the solution becomes easier to find. If it’s a world issue, you can search for solutions online or restore a backup. With so many possible errors, it’s impossible to cover each one here, but understanding how to read crash reports will guide you in resolving most issues.