flowable/flowable-engine · error · FlowableException

Cannot add a comment to a suspended {execution}

Error message

Cannot add a comment to a suspended {execution}

What it means

FlowableException thrown by AddCommentCmd.execute when the process instance execution exists but is suspended. Comments cannot be added to suspended process instances; the instance must be activated first.

Source

Thrown at modules/flowable-engine/src/main/java/org/flowable/engine/impl/cmd/AddCommentCmd.java:82

            if (task == null) {
                throw new FlowableObjectNotFoundException("Cannot find task with id " + taskId, Task.class);
            }

            if (task.isSuspended()) {
                throw new FlowableException("Cannot add a comment to a suspended " + task);
            }
        }

        ExecutionEntity execution = null;
        if (processInstanceId != null) {
            execution = processEngineConfiguration.getExecutionEntityManager().findById(processInstanceId);

            if (execution == null) {
                throw new FlowableObjectNotFoundException("execution " + processInstanceId + " doesn't exist", Execution.class);
            }

            if (execution.isSuspended()) {
                throw new FlowableException("Cannot add a comment to a suspended " + execution);
            }
        }

        String processDefinitionId = null;
        if (execution != null) {
            processDefinitionId = execution.getProcessDefinitionId();
        } else if (task != null) {
            processDefinitionId = task.getProcessDefinitionId();
        }

        if (Flowable5Util.isFlowable5ProcessDefinitionId(commandContext, processDefinitionId)) {
            Flowable5CompatibilityHandler compatibilityHandler = Flowable5Util.getFlowable5CompatibilityHandler();
            return compatibilityHandler.addComment(taskId, processInstanceId, type, message);
        }

        String userId = Authentication.getAuthenticatedUserId();
        CommentEntity comment = processEngineConfiguration.getCommentEntityManager().create();
        comment.setUserId(userId);

View on GitHub (pinned to d6d39ce1c6)

Solutions

1. Activate the process instance first: runtimeService.activateProcessInstanceById(processInstanceId), then add the comment.
2. If suspension came from the process definition, activate the definition: runtimeService.activateProcessInstanceByKey(key).
3. Check execution.isSuspended() (processInstanceQuery().suspended()/active()) before commenting.
4. Catch FlowableException and defer/queue comments until the instance is active.

Example fix

// before
taskService.addComment(null, processInstanceId, msg);
// after
if (runtimeService.createProcessInstanceQuery()
        .processInstanceId(processInstanceId).active().singleResult() != null) {
    taskService.addComment(null, processInstanceId, msg);
} else {
    runtimeService.activateProcessInstanceById(processInstanceId);
    taskService.addComment(null, processInstanceId, msg);
}

if (runtimeService.createProcessInstanceQuery()
        .processInstanceId(processInstanceId).suspended().singleResult() != null) {
    runtimeService.activateProcessInstanceById(processInstanceId);
}

try {
    taskService.addComment(null, processInstanceId, msg);
} catch (FlowableException e) {
    // queue and retry after the instance is activated
    commentQueue.add(new PendingComment(processInstanceId, msg));
}

When it happens

Trigger: taskService.addComment(null, processInstanceId, message) while the instance is suspended via runtimeService.suspendProcessInstanceById or a suspended process definition.

Common situations: Workflow paused for maintenance or business hold while integrations keep posting comments; scheduled comment jobs overlapping a suspension window.

Understand the failure class

Background: "Invalid state transition" errors: "status must be X, actually Y", "already rejected/charging/uninstalled", "cannot ... while running" — what they mean when a library rejects your call — this error's family across 31 libraries.

Related errors

• Cannot add a comment to a suspended {task}
• execution {processInstanceId} doesn't exist
• process instance ${processInstanceId} is suspended, cannot s
• Could not start process instance with business key ${key}
• Job <jobId> parent is not process instance

AI-assisted analysis of flowable/flowable-engine@d6d39ce1c6 (2026-09-11). Data as JSON: /api/errors/b555e32e4ba0afec. Report an issue: GitHub.