Fix Minecraft crashes and launcher errors (Java and Bedrock)

Open the newest file in the crash-reports folder of .minecraft and read the Description line and the lines just below it: they name what failed. Most crashes come from a mod made for another version or loader, too little memory, the wrong Java, a graphics driver or a broken data pack, and each has a fix below. If there is no crash report, the logs tell you instead.

• Exit Code: -1 is the code the game uses when it crashes. A crash report was written: go to the next step.
• Another exit code, or a game that closes before its window opens: the game did not get far enough to write a report. Skip to the logs.
• The launcher itself will not open, update or sign in: go to the last step.

Open the .minecraft folder (%appdata%\.minecraft on Windows, ~/Library/Application Support/minecraft on macOS, ~/.minecraft on Linux), then crash-reports, and pick the newest file. It starts like this:

• ---- Minecraft Crash Report ----
• a line starting with //: a random joke, ignore it;
• Time: and Description:, the short name of the error;
• the error itself, then a list of lines starting with at.

The error line and the first at lines are what matter. A mod name or a mod's package name there points to the culprit. Mod launchers keep crash-reports inside each instance's folder.

• logs/latest.log in .minecraft: everything the game printed during the last session. Read the last lines.
• launcher_log.txt in .minecraft: what the launcher did, including the Java it started.
• A file starting with hs_err_pid in .minecraft: Java itself crashed, often because of a graphics driver.

To watch the log live, turn on "Open output log when the game starts" in the launcher settings.

• Wrong loader: a Fabric mod does not load with NeoForge, and the reverse.
• Wrong version: the mod file must be built for your exact Minecraft version.
• Missing dependency: many Fabric mods need Fabric API in the mods folder.
• No name in the report: move half of the mods out of the mods folder and start again. Keep halving the group that crashes until one mod is left.

Clean installs are explained in how to install Fabric and how to install NeoForge or Forge.

The "Out of memory!" screen, or java.lang.OutOfMemoryError in a log, means the game ran out of RAM: give it more, as shown in how to allocate more RAM. An error about the Java version appears when an installation uses your own Java executable instead of the launcher's. Each version needs its own:

• Update your graphics driver from the website of your graphics card's maker.
• In 26.3, Options, Video Settings has a Graphics API setting. If you chose "Prefer Vulkan (Experimental)" and the game now crashes, set it back to Default and restart the game.
• If the game crashes before you can reach that menu, open options.txt in .minecraft and set the preferredGraphicsBackend line to default.
• Remove shaders and resource packs one at a time: a pack made for another version can crash the game at loading.

• A broken data pack: the game offers Safe Mode, which opens the world with the vanilla data only. Then remove the pack from the world's datapacks folder.
• "Failed to upgrade the world": this usually means another program used the world folder during the upgrade. Close cloud sync and backup tools, restart the computer and try again.
• A world that still crashes: restore the copy made with Make Backup, from the Open Backups Folder button on the world's Edit screen.

• Minecraft Launcher: download it again from minecraft.net. On Windows, you can also open Settings, Apps, Installed apps, then the launcher's Advanced options, and use Repair, then Reset if needed.
• Bedrock Edition: install the latest update from your device's store, turn off global resource packs and add-ons, then restart the device. On Windows, Repair and Reset work the same way for the Minecraft app.