Launcher problems

HMCL ChecksumMismatchException: Incorrect Checksum (SHA-1) During Forge/NeoForge Install

What it looks like in the log

org.jackhuang.hmcl.util.io.ChecksumMismatchException: Incorrect checksum (SHA-1), expected: de86b035d2da0f78940796bb95c39a932ed84834, actual: 194fcc11

How to fix it

  1. Update HMCL to the latest stable or development version, which includes fixes for Forge installer processor checksum verification.
  2. If you are on Fedora or another Linux distribution using zlib-ng, run HMCL and the game installer with a standalone JDK (such as Adoptium Temurin or Azul Zulu tar.gz) rather than the system OpenJDK package, as standalone JDKs bundle standard zlib.
  3. In HMCL Settings > Download, change the download source to Official instead of a mirror to rule out out-of-sync mirror files.
  4. Delete the failed game version folder if one was created, then retry installing Forge, NeoForge, or the modpack.
LoadersForge, Neoforge
SeverityBreaks something
CategoryLauncher problems

Check your own log

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