HMCL-dev/HMCL · error · ArtifactMalformedException

Invalid forge installation configuration

Error message

Invalid forge installation configuration

What it means

NeoForgeOldInstallTask.execute() parses the old-style Forge installer's configuration (the processed `data` map of install_profile), substituting variables in each key/value. If substitution leaves either key or value null, the configuration cannot describe a valid artifact mapping, and ArtifactMalformedException is thrown — the installer profile is unusable.

Solutions

1. Re-download the installer (clear cache) to rule out a corrupt jar.
2. Update HMCL so all expected profile variables are supported for this installer version.
3. Make sure the correct task/installer pathway is used for legacy vs modern Forge versions.
4. Verify the installer's install_profile.json manually to spot unsupported variables.

Example fix

// Not caller-fixable; typical recovery:
// delete <cache>/neoforge/<installer>.jar, update HMCL, retry installation

// Before install, ensure all variables referenced by data literals exist
for (String lit : dataMap.values()) for (String var : extractVars(lit)) if (!vars.containsKey(var)) throw new IllegalStateException("Missing var: " + var);

if (key == null || value == null) { markInstallerCorrupt(); }

try { oldInstallTask.run(); } catch (ArtifactMalformedException e) {
    LOG.warning("Forge installer config invalid: " + e.getMessage(), e);
    Files.deleteIfExists(installerJar); // redownload and retry
}

When it happens

Trigger: Parsing a legacy Forge/NeoForge installer's data map where parseLiteral(key, vars) or parseLiteral(value, vars) returns null — e.g. a variable referenced in the literal is missing from `vars`, or the literal format is unrecognized.

Common situations: A corrupted or tampered old Forge installer jar; an installer version whose install_profile data entries reference variables HMCL doesn't provide; mixing up installer versions with game versions (old installer fed to the modern task or vice versa).

Understand the failure class

Background: "Invalid value" and "allowed values are" config errors: what your library rejected and how to fix it — this error's family across 41 libraries.

Related errors

• ForgeNewInstallProfile is malformed
• Invalid neoforge version.
• Account private data is not an object
• authlib-injectors.json -> urls cannot be null.
• Game directory ID cannot be null

AI-assisted analysis of HMCL-dev/HMCL@24702dc5a0 (2026-09-10). Data as JSON: /api/errors/71e60313b4c51d67. Report an issue: GitHub.

Appendix: source

Thrown at HMCLCore/src/main/java/org/jackhuang/hmcl/download/neoforge/NeoForgeOldInstallTask.java:85

            this.processor = processor;
            this.vars = vars;
            setSignificance(TaskSignificance.MODERATE);
        }

        @Override
        public void execute() throws Exception {
            Map<String, String> outputs = new HashMap<>();
            boolean miss = false;

            for (Map.Entry<String, String> entry : processor.getOutputs().entrySet()) {
                String key = entry.getKey();
                String value = entry.getValue();

                key = parseLiteral(key, vars);
                value = parseLiteral(value, vars);

                if (key == null || value == null) {
                    throw new ArtifactMalformedException("Invalid forge installation configuration");
                }

                outputs.put(key, value);

                Path artifact = Paths.get(key);
                if (Files.exists(artifact)) {
                    String code;
                    try (InputStream stream = Files.newInputStream(artifact)) {
                        code = (DigestUtils.digestToString("SHA-1", stream));
                    }

                    if (!Objects.equals(code, value)) {
                        Files.delete(artifact);
                        LOG.info("Found existing file is not valid: " + artifact);

                        miss = true;
                    }
                } else {

View on GitHub (pinned to 24702dc5a0)