flowable/flowable-engine · error · FlowableException

unsupported variable scope type:

Error message

unsupported variable scope type: 

What it means

FlowableException thrown by the VariableScopeResolver constructor when scopeContainer is neither an ExecutionEntity nor a TaskEntity. The resolver only knows how to map these two variable scope types to a variableScopeKey ('execution' or 'task').

Source

Thrown at modules/flowable-engine/src/main/java/org/flowable/engine/impl/scripting/VariableScopeResolver.java:65

            "identityService", ProcessEngineConfiguration::getIdentityService,
            // the identity service was historically exposed under this name, kept for backwards compatibility
            "identityServiceKey", ProcessEngineConfiguration::getIdentityService
    );

    public VariableScopeResolver(ProcessEngineConfigurationImpl processEngineConfiguration, VariableContainer scopeContainer,
            VariableContainer inputVariableContainer) {

        this.processEngineConfiguration = processEngineConfiguration;

        if (scopeContainer == null) {
            throw new FlowableIllegalArgumentException("scopeContainer cannot be null");
        }
        if (scopeContainer instanceof ExecutionEntity) {
            variableScopeKey = "execution";
        } else if (scopeContainer instanceof TaskEntity) {
            variableScopeKey = "task";
        } else {
            throw new FlowableException("unsupported variable scope type: " + scopeContainer.getClass().getName());
        }
        this.scopeContainer = scopeContainer;
        this.inputVariableContainer = inputVariableContainer;
    }

    @Override
    public boolean containsKey(Object key) {
        return variableScopeKey.equals(key) || inputVariableContainer.hasVariable((String) key)
                || SERVICE_RESOLVERS.containsKey(key) && processEngineConfiguration.isServicesEnabledInScripting();
    }

    @Override
    public Object get(Object key) {
        if (variableScopeKey.equals(key)) {
            return scopeContainer;
        } else if (SERVICE_RESOLVERS.containsKey((String) key)) {
            if (processEngineConfiguration.isServicesEnabledInScripting()) {
                return SERVICE_RESOLVERS.get(key).apply(processEngineConfiguration);

View on GitHub (pinned to d6d39ce1c6)

Solutions

1. Pass the actual DelegateExecution (ExecutionEntity) or DelegateTask (TaskEntity) instead of a generic VariableContainer.
2. In tests, mock ExecutionEntity/TaskEntity types rather than the VariableContainer interface.
3. If a new scope type is genuinely needed, register/extend the resolver rather than feeding unsupported containers into this constructor.

Example fix

// before
new VariableScopeResolver(config, myCustomVariableContainer, inputVariables);

// after
new VariableScopeResolver(config, (VariableContainer) executionEntity, inputVariables);

if (!(scope instanceof ExecutionEntity) && !(scope instanceof TaskEntity)) {
    throw new IllegalArgumentException("scope must be ExecutionEntity or TaskEntity, got "
        + (scope == null ? "null" : scope.getClass().getName()));
}

boolean isSupportedScope(VariableContainer c) {
    return c instanceof ExecutionEntity || c instanceof TaskEntity;
}

try {
    resolver = new VariableScopeResolver(config, scope, inputVars);
} catch (FlowableException e) {
    log.error("unsupported scope type: {}", e.getMessage());
    throw e;
}

When it happens

Trigger: Constructing VariableScopeResolver with a custom VariableContainer implementation, a CaseInstance/other scope type, or a mock/stub of VariableContainer in tests that is not ExecutionEntity/TaskEntity.

Common situations: Unit tests passing Mockito mocks of VariableContainer; custom scripting integrations passing CaseTask or standalone variable containers; Flowable version changes where new scope types are not supported by this resolver.

Understand the failure class

Background: "Must be a positive integer", "Invalid value", "Unsupported": the invalid-argument-value error family, when a library rejects the value you pass — this error's family across 35 libraries.

Related errors

• 'language' evaluated to null for taskListener of type 'scrip
• Script content is null or evaluated to null for taskListener
• scopeContainer cannot be null
• The service '${key}' is not available in the current context
• Unsupported variableContainer for key '${CASE_INSTANCE_KEY}'

AI-assisted analysis of flowable/flowable-engine@d6d39ce1c6 (2026-09-11). Data as JSON: /api/errors/9244bb33554dd7de. Report an issue: GitHub.