flowable/flowable-engine · error · IllegalStateException

Event registry has not been initialized

Error message

Event registry has not been initialized

What it means

The EventRegistryServicesAutoConfiguration exposes the already-initialized event registry engine from the static EventRegistryEngines registry as a Spring bean. If no event registry engine has been initialized when the bean method runs, it throws this IllegalStateException. The injected ProcessEngine is expected to have bootstrapped the event registry engine.

Solutions

1. Ensure the ProcessEngine auto-configuration runs and includes the event registry configurator
2. Add/verify flowable-event-registry-spring-configurator in the engine configuration
3. Let auto-configuration build a standalone EventRegistryEngineConfiguration bean instead of using the already-initialized bean
4. Check for earlier engine-init failures in logs that left EventRegistryEngines uninitialized

Example fix

// before: process engine built without event registry
ProcessEngineConfiguration.createProcessEngineConfigurationFromResourceDefault();
// after: register the configurator
config.addConfigurator(new EventRegistryEngineConfigurator());

if (!EventRegistryEngines.isInitialized()) { throw new IllegalStateException("Initialize the event registry engine before requesting the bean"); }

boolean eventRegistryAvailable = EventRegistryEngines.isInitialized();

try { return EventRegistryEngines.getDefaultEventRegistryEngine(); } catch (IllegalStateException e) { /* build EventRegistryEngineConfiguration locally */ }

When it happens

Trigger: Auto-configuration selects AlreadyInitializedEventRegistryConfiguration and eventRegistryEngine(ProcessEngine) runs while EventRegistryEngines.isInitialized() is false — no engine bootstrap initialized an EventRegistryEngine beforehand.

Common situations: Event registry starter present but process engine excluded or failing; manual engine configuration bypassing auto-configuration; missing event-registry dependency in a multi-engine setup.

Related errors

• DMN engine has not been initialized
• Idm engine has not been initialized
• A channel key detection value is required for inbound…
• A channel key detection value is required for the channel…
• A resource name is mandatory

AI-assisted analysis of flowable/flowable-engine@d6d39ce1c6 (2026-09-11). Data as JSON: /api/errors/512f0351762eb6e2. Report an issue: GitHub.

Appendix: source

Thrown at modules/flowable-spring-boot/flowable-spring-boot-starters/flowable-spring-boot-autoconfigure/src/main/java/org/flowable/spring/boot/eventregistry/EventRegistryServicesAutoConfiguration.java:72

    /**
     * If a process engine is present that means that the EventRegistryEngine was created as part of it.
     * Therefore extract it from the EventRegistryEngines.
     */
    @Configuration(proxyBeanMethods = false)
    @ConditionalOnMissingBean(type = {
        "org.flowable.eventregistry.impl.EventRegistryEngine",
        "org.flowable.app.engine.AppEngine"
    })
    @ConditionalOnBean(type = {
        "org.flowable.engine.ProcessEngine"
    })
    static class AlreadyInitializedEventRegistryConfiguration {
        @Bean
        public EventRegistryEngine eventRegistryEngine(@SuppressWarnings("unused") ProcessEngine processEngine) {
            // The process engine needs to be injected, as otherwise it won't be initialized, which means that the EventRegistryEngine is not initialized yet
            if (!EventRegistryEngines.isInitialized()) {
                throw new IllegalStateException("Event registry has not been initialized");
            }
            return EventRegistryEngines.getDefaultEventRegistryEngine();
        }
    }
    
    /**
     * If an app engine is present that means that the EventRegistryEngine was created as part of the app engine.
     * Therefore extract it from the EventRegistryEngines.
     */
    @Configuration(proxyBeanMethods = false)
    @ConditionalOnMissingBean(type = {
        "org.flowable.eventregistry.impl.EventRegistryEngine"
    })
    @ConditionalOnBean(type = {
        "org.flowable.app.engine.AppEngine"
    })
    static class AlreadyInitializedAppEngineConfiguration {

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