Launcher problems

HMCL Failed to Download authlib-injector

What it looks like in the log

java.io.IOException: Failed to download authlib-injector

How to fix it

  1. Update HMCL to the latest release (newer than 3.6.14) to fix the startup race condition between the authlib-injector updater and HMCL's local cache initialization.
  2. If the stack trace shows a NullPointerException in CacheRepository and you do not use a third-party authentication server, ignore the warning—it is harmless and does not cause launcher crashes.
  3. Open HMCL Settings -> Download and switch the Download Source (for example, from BMCLAPI to Official or Balanced) if the download URL is timing out.
  4. If you use a third-party skin/login server and HMCL still cannot download the file, manually download the latest authlib-injector JAR, rename it to authlib-injector.jar, and place it into .hmcl/dependencies/universal/ (either next to your HMCL executable or inside %AppData%\.hmcl\dependencies\universal\).
LoadersVanilla, Forge, Neoforge, Fabric, Quilt
SeverityWorth checking
CategoryLauncher problems

Check your own log

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