Minecraft: error 1 Exit Code 1

Error starting Java Edition

Find the reason for the crash using the log and correct the specific error.

My game select version

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Briefly

Exit Code 1 means that the game process has been completed with error. The number itself does not explain why: it needs to be searched in the log of the last launch. Save latest.log until the next launch and select it below.

Where to Find the Real Reason

  1. Open The game profile folderwhich crashed. The folders are different for different assemblies.
  2. Save the file logs/latest.log last failed launch. If there is a new report in crash-reports, save that too. Check the date of the files.
  3. If there are no new files, open the startup log in the launcher: the process may have ended before Minecraft started.
  4. Paste the log into the form below. One last line Process exited with code 1 is not enough.

Before changing the build, save a copy of the profile and worlds. The current launch log may overwrite the previous one.

Parse log

The log is parsed in memory and is not saved anywhere. It contains the nickname and path to the user's folder - we do not store them.

Four examples: the string log action

These are short examples to compare with your log, not a full report of one flight. The completion code does not itself choose the appropriate case.

Missing dependencies or mismatched mod versions

Incompatible mods found!
Mod 'Example' (example) requires any version of fabric-api, which is missing!

In this example, Fabric requests the Fabric API. The names and required versions in your log will be different.

  1. Find the lines requires, which is missing or wrong version. They call it a mod, a dependency, and a valid version.
  2. Install the specified dependency for your version of Minecraft and bootloader. The Forge file does not replace the Fabric file.
  3. In the finished modpack, first restore its original composition. Don't update individual mods at random.

A detailed solution to this error

Game launches with inappropriate Java

java.lang.UnsupportedClassVersionError: Example has been compiled by a more recent version of the Java Runtime (class file version 65.0), this version of the Java Runtime only recognizes class file versions up to 61.0

This fragment means: the component was built for Java 21, and launched on Java 17.

  1. Check the Java version and path in the game profile settings and in the launch log. Java in the terminal may be different.
  2. Select the Java required by your specific game version, loader, and build. Installing the latest Java does not fix all older builds.
  3. If the launcher itself selects the environment, return automatic selection instead of a random path to java.exe.

A detailed solution to this error

The mod was unable to apply the change to the game code

org.spongepowered.asm.mixin.transformer.throwables.MixinTransformerError
Mixin [example.mixins.json:ExampleMixin] from phase [DEFAULT] in config [example.mixins.json] FAILED during APPLY

This is a Mixin application error. The name next to it helps to start the check, but in itself does not prove that only this mod is to blame.

  1. Read the entire Caused by thread and the messages before it: the reason may be in the game version, dependency or interaction of mods.
  2. In the profile copy, undo the last change. Test one step at a time and keep required dependencies.
  3. Check with the authors of the affected mods for supported versions. Don't migrate your production world to an incomplete build for the sake of testing the launch.

A detailed solution to this error

Java could not allocate memory

Error occurred during initialization of VM
Could not reserve enough space for object heap

The environment was unable to reserve the requested memory. This is different from OutOfMemoryError already during the game.

  1. Check the amount of memory in the profile and the -Xmx value. Leave the memory to Windows and other applications.
  2. Make sure the profile uses the appropriate 64-bit Java; remove accidentally copied JVM parameters.
  3. If there is a different line in the log - OutOfMemoryError - open a separate analysis of out of memory, and do not apply this recipe blindly.

A detailed solution to this error

Useful references: What Java needs is Minecraft, How to mod, OutOfMemoryError during the game.

If the cause has not yet been found

  1. Create a separate clean profile of the same version of Minecraft with a suitable Java. Start to the main menu, then check the new test world.
  2. If a clean game also crashes, check its new log. Subject to availability hs_err_pid save this Java report: it may indicate a native failure, for example in a driver.
  3. If a clean game starts, add the right loader and its mandatory relationships. In copies of the assembly, return the changes one by checking the start-up each time.
  4. If the error remains, prepare a version of Minecraft, a downloader and Java, a list of recent changes and a full log. Check it for access currents and personal data before sending it to the public.

Don't delete the game's shared folder or load random DLLs just for the sake of code. To fix it, you need a specific error line.

Sources

Checked 2026-11-09.

Frequently asked questions

Exit Code 1 always means wrong Java?

No. Code 1 reports that the process has failed. The reasons are shown in the log lines: these may be Java, mods, addictions, or other launch failure.

Why is there no crash-reports folder?

Not every malfunction is able to create the Minecraft report. Open logs/latest.log in the right profile folder, and if the game has not started writing a log, the Launcher launch log.

Do I need to delete .minecraft to fix code 1?

Start with the log and separate clean profile of the same version. The removal of a common folder can destroy worlds, images and settings and does not explain the cause of the error.

More on the wiki

Entire Wiki

Based on Java and Fabric documentation. Example strings have been shortened; The names of the mods are conditional.