HMCL-dev/HMCL · error · JsonParseException

McbbsModpackManifest.addons cannot be null

Error message

McbbsModpackManifest.addons cannot be null

What it means

Post-deserialization validation of an MCBBS modpack manifest: the 'addons' array is absent or null. Addons record component versions (e.g. forge, fabric), and without them HMCL cannot build the game instance, so the manifest is rejected.

Solutions

  1. Re-download the modpack archive; it may be corrupted or incomplete
  2. Check that mcbbs.packmeta includes a non-null addons array
Defensive patterns

Strategy: validation

When it happens

Trigger: Thrown at HMCLCore/src/main/java/org/jackhuang/hmcl/modpack/mcbbs/McbbsModpackManifest.java:165 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of HMCL-dev/HMCL@24702dc5a0 (2026-09-10). Data as JSON: /api/errors/f4a96459efa6c9ba. Report an issue: GitHub.

Appendix: source

Thrown at HMCLCore/src/main/java/org/jackhuang/hmcl/modpack/mcbbs/McbbsModpackManifest.java:165

@Override
public void validate() throws JsonParseException, TolerableValidationException {
    if (!MANIFEST_TYPE.equals(manifestType))
        throw new JsonParseException("McbbsModpackManifest.manifestType must be 'minecraftModpack'");
    if (files == null)
        throw new JsonParseException("McbbsModpackManifest.files cannot be null");
    if (addons == null)
        throw new JsonParseException("McbbsModpackManifest.addons cannot be null");
}

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