criticalLauncher ErrorsAffects: 1.21+
How to Fix Java 21 Required for 1.21+
Fix Java 21 Required by installing Java 21 from Adoptium and setting it in your launcher.
Quick Fix
Install Java 21 from Adoptium (adoptium.net) and configure your launcher to use it.
Error Message
Minecraft 1.21 requires Java 21 or newerHow to Fix
1
Download Java 21 from adoptium.net
2
Install it and set the path in your launcher
3
The official Mojang launcher bundles the correct Java automatically
4
For Prism/MultiMC: Settings > Java > Auto-detect or set path manually
Common Causes
- System Java is older than Java 21
- Launcher using wrong Java installation
- Third-party launcher not auto-detecting Java 21
Diagnostic Steps
- Download Java 21 from adoptium.net
- Install it
- Configure launcher Java path
- Launch the game
FAQ
Do I need to uninstall old Java?
Not required but recommended to avoid confusion. Multiple Java versions can coexist.