flowable/flowable-engine · error · FlowableException

Invalid sourceElementId

Error message

Invalid sourceElementId '${sourceElementId}': no element found for this id n process definition '${processDefinitionId}'

What it means

ExecutionGraphUtil.isReachable validates that the source element id can be resolved to a FlowNode in the deployed process model before doing a graph traversal. When BpmnModel.getElementById (or equivalent lookup) returns nothing for sourceElementId, Flowable throws this FlowableException because reachability cannot be computed from a nonexistent element.

Solutions

Verify the sourceElementId exists in the current process definition (inspect the BPMN XML or use BpmnModel.getElementById) and correct the id.
Make sure you reference the same process definition version — pass the exact processDefinitionId of the deployed definition containing the element.
Check whether the definition was redeployed and element ids were regenerated; update callers accordingly.
Null-check the element in caller code against the model before invoking isReachable.

Example fix

// before
boolean ok = executionGraphUtil.isReachable("procDef:1", "wrongTaskId", "endEvent");

// after
BpmnModel model = repositoryService.getBpmnModel(processDefinitionId);
if (model.getFlowElement("startTask") != null) {
    boolean ok = executionGraphUtil.isReachable(processDefinitionId, "startTask", "endEvent");
}

Defensive patterns

Strategy: validation

Validate before calling

BpmnModel model = repositoryService.getBpmnModel(processDefinitionId);
if (model.getFlowElement(sourceElementId) == null) {
    throw new IllegalArgumentException("sourceElementId " + sourceElementId + " not in " + processDefinitionId);
}

Prevention

Resolve element ids from the same process definition version you pass in
Never hardcode element ids across deployments; read them from the model
Validate BPMN ids after diagram edits before programmatic use

When it happens

Trigger: Calling the public isReachable(processDefinitionId, sourceElementId, targetElementId) API where sourceElementId does not match any flow element in the process definition resolved from the repository/deployment cache.

Common situations: Typo in the element id; using an id from a different (older/newer) process definition version; passing a sequence-flow id as the source where a flow node is required and the lookup fails; ids from a process definition that was redeployed or deleted.

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

AI-assisted analysis of flowable/flowable-engine@d6d39ce1c6 (2026-09-11). Data as JSON: /api/errors/2c809f392a830c26. Report an issue: GitHub.

Appendix: source

Thrown at modules/flowable-engine/src/main/java/org/flowable/engine/impl/util/ExecutionGraphUtil.java:62

        FlowElement sourceFlowElement = process.getFlowElement(sourceElementId, true);
        FlowNode sourceElement = null;
        if (sourceFlowElement instanceof FlowNode) {
            sourceElement = (FlowNode) sourceFlowElement;
        } else if (sourceFlowElement instanceof SequenceFlow) {
            sourceElement = (FlowNode) ((SequenceFlow) sourceFlowElement).getTargetFlowElement();
        }

        FlowElement targetFlowElement = process.getFlowElement(targetElementId, true);
        FlowNode targetElement = null;
        if (targetFlowElement instanceof FlowNode) {
            targetElement = (FlowNode) targetFlowElement;
        } else if (targetFlowElement instanceof SequenceFlow) {
            targetElement = (FlowNode) ((SequenceFlow) targetFlowElement).getTargetFlowElement();
        }

        if (sourceElement == null) {
            throw new FlowableException("Invalid sourceElementId '" + sourceElementId + "': no element found for this id n process definition '" + processDefinitionId + "'");
        }
        if (targetElement == null) {
            throw new FlowableException("Invalid targetElementId '" + targetElementId + "': no element found for this id n process definition '" + processDefinitionId + "'");
        }

        Set<String> visitedElements = new HashSet<>();
        return isReachable(process, sourceElement, targetElement, visitedElements);
    }

    public static boolean isReachable(Process process, FlowNode sourceElement, FlowNode targetElement, Set<String> visitedElements) {
        
        // Special case: start events in an event subprocess might exist as an execution and are most likely be able to reach the target
        // when the target is in the event subprocess, but should be ignored as they are not 'real' runtime executions (but rather waiting for a trigger)
        if (sourceElement instanceof StartEvent && isInEventSubprocess(sourceElement)) {
            return false;
        }

        // No outgoing seq flow: could be the end of eg . the process or an embedded subprocess

View on GitHub (pinned to d6d39ce1c6)