flowable/flowable-engine · error · FlowableIllegalArgumentException

version is null

Error message

version is null

What it means

ModelQueryImpl.modelVersion filters models by an exact version number. Besides rejecting null with FlowableIllegalArgumentException, it also rejects versions <= 0 with 'version must be positive', since model versions start at 1. This validates that the filter is a meaningful positive integer.

Source

Thrown at modules/flowable-engine/src/main/java/org/flowable/engine/impl/ModelQueryImpl.java:123

            throw new FlowableIllegalArgumentException("nameLike is null");
        }
        this.nameLike = nameLike;
        return this;
    }

    @Override
    public ModelQuery modelKey(String key) {
        if (key == null) {
            throw new FlowableIllegalArgumentException("key is null");
        }
        this.key = key;
        return this;
    }

    @Override
    public ModelQueryImpl modelVersion(Integer version) {
        if (version == null) {
            throw new FlowableIllegalArgumentException("version is null");
        } else if (version <= 0) {
            throw new FlowableIllegalArgumentException("version must be positive");
        }
        this.version = version;
        return this;
    }

    @Override
    public ModelQuery latestVersion() {
        this.latest = true;
        return this;
    }

    @Override
    public ModelQuery deploymentId(String deploymentId) {
        if (deploymentId == null) {
            throw new FlowableIllegalArgumentException("DeploymentId is null");
        }

View on GitHub (pinned to d6d39ce1c6)

Solutions

1. Pass a positive, non-null Integer (versions start at 1); to get the latest use latestVersion() instead of modelVersion
2. Null-check and range-check the value before calling
3. Ensure version parsing throws/handles failures instead of defaulting to 0
4. Validate the incoming request field as a positive integer with a clear client-side message

Example fix

// before
ModelQuery q = repositoryService.createModelQuery()
    .modelVersion(parseVersion(request.getVersion())); // may be null or 0
// after
Integer version = parseVersion(request.getVersion());
if (version == null || version <= 0) {
    throw new BadRequestException("version must be a positive integer");
}
ModelQuery q = repositoryService.createModelQuery().modelVersion(version);

if (version != null && version > 0) { query = query.modelVersion(version); }

boolean isValidVersion(Integer v) { return v != null && v > 0; }

try {
    List<Model> models = query.modelVersion(version).list();
} catch (FlowableIllegalArgumentException e) {
    log.warn("Bad version filter: {}", e.getMessage());
}

When it happens

Trigger: Calling repositoryService.createModelQuery().modelVersion(version) with a null Integer, or with a version parsed as 0/negative from user input or a failed parseInt default.

Common situations: UIs selecting a specific model version where the selection defaulted to null; parsing version strings where NumberFormatException is swallowed and a 0 is used; pagination code producing off-by-zero version values.

Related errors

• appsDefinitionIds is null
• category is null
• query is null
• parentScopeIds is null or empty
• Business status is null

AI-assisted analysis of flowable/flowable-engine@d6d39ce1c6 (2026-09-11). Data as JSON: /api/errors/5dd5a607d594926e. Report an issue: GitHub.