HMCL-dev/HMCL · error · JsonParseException

CurseForge Manifest.gameVersion cannot be blank.

Error message

CurseForge Manifest.gameVersion cannot be blank.

What it means

Post-deserialization validation of the 'minecraft' section of a CurseForge manifest: gameVersion (mapped from the 'version' JSON field) must be non-blank, otherwise the modpack's target Minecraft version is unknown and the manifest is rejected.

Solutions

1. Set minecraft.gameVersion to a valid Minecraft version (e.g. "1.20.1") in manifest.json
2. Re-export the modpack from the CurseForge app
3. Use a different source archive whose manifest is complete

Example fix

// before
{"minecraft":{"version":"1.0.0","modLoaders":[...]}}
// after
{"minecraft":{"version":"1.0.0","gameVersion":"1.20.1","modLoaders":[...]}}

if (manifest.getMinecraft() == null || isBlank(manifest.getMinecraft().getGameVersion())) { /* reject manifest before install */ }

boolean hasGameVersion(CurseManifestMinecraft m) { return m != null && m.getGameVersion() != null && !m.getGameVersion().isBlank(); }

try { minecraft.validate(); } catch (JsonParseException e) { log.error("Manifest missing gameVersion", e); }

When it happens

Trigger: Parsing a curse manifest.json whose minecraft.gameVersion is empty, whitespace-only, or absent, then calling validate().

Common situations: Incomplete/buggy manifest export, hand-edited manifest where gameVersion was deleted, minimal test manifests missing required fields.

Understand the failure class

Background: "must not be empty", "cannot be empty" — required-field validation errors across open-source libraries — this error's family across 41 libraries.

Related errors

• Instance
• Missing Project ID or File ID.
• Curse Forge modpack manifest Mod loader id cannot be blank.
• Invalid library path:
• /assets/

AI-assisted analysis of HMCL-dev/HMCL@24702dc5a0 (2026-09-10). Data as JSON: /api/errors/52cedbb7bb6fc121. Report an issue: GitHub.

Appendix: source

Thrown at HMCLCore/src/main/java/org/jackhuang/hmcl/modpack/curse/CurseManifestMinecraft.java:48

@Override
public void validate() throws JsonParseException {
    if (StringUtils.isBlank(gameVersion))
        throw new JsonParseException("CurseForge Manifest.gameVersion cannot be blank.");
}

View on GitHub (pinned to 24702dc5a0)