If you have received the following error:

Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'NSWindow drag regions should only be invalidated on the Main Thread!'

on macOS when starting Minecraft, you will have to install an older version of Java.

To do so:

• First, uninstall the currently installed Java version, following this guide: https://explainjava.com/uninstall-java-macos/
• Then download and install a compatible Java distribution such as:
  • Eclipse Temurin (recommended)
  • Azul Zulu Ensure you install Java 8 for older Minecraft versions.
• After selecting the newly installed Java, you should be able to play normally.