flowable/flowable-engine · error · FlowableObjectNotFoundException

task " + taskId + " doesn't exist

Error message

task " + taskId + " doesn't exist

What it means

FlowableObjectNotFoundException (Task.class) thrown by GetTaskVariableInstancesCmd.execute when no task exists for the given taskId. The lookup via the task service returns null and the command aborts before assembling the variables map; the variableNames/isLocal parameters are never consulted.

Solutions

1. Existence-check with taskService.createTaskQuery().taskId(taskId).count() before fetching variables
2. Confirm all nodes/environments point at the shared engine database
3. For completed tasks, use historyService.createHistoricTaskInstanceQuery / HistoricVariableInstanceQuery
4. Catch FlowableObjectNotFoundException and return an idempotent not-found result in batch workers

Example fix

// before
Map<String, VariableInstance> vars = taskService.getTaskVariableInstances(taskId);
// after
if (taskService.createTaskQuery().taskId(taskId).count() == 0) {
    return Collections.emptyMap(); // or throw domain-specific NotFound
}
Map<String, VariableInstance> vars = taskService.getTaskVariableInstances(taskId);

boolean exists = taskService.createTaskQuery().taskId(taskId).count() > 0;

try {
    Map<String, VariableInstance> vars = taskService.getTaskVariableInstances(taskId);
} catch (FlowableObjectNotFoundException e) {
    respond(404, "Task " + taskId + " does not exist");
}

When it happens

Trigger: taskService.getTaskVariableInstances(taskId) with an id for a task that never existed, was deleted, was completed with runtime data cleared, or lives in another database/tenant; filtering with a variableNames list cannot rescue a missing task.

Common situations: Polling job still processing a task id after process termination; cluster nodes sharing a load balancer but not the same engine database; tests reusing ids from a truncated schema.

Understand the failure class

Background: "Not found" and "does not exist" errors: why "Task not found", "No such folder", and "Can't find" fire when a lookup comes back empty — this error's family across 14 libraries.

Related errors

• task
• task " + taskId + " doesn't exist
• Cannot find task with id " + taskId
• Cannot find task with id " + taskId
• Cannot set global variables on execution

AI-assisted analysis of flowable/flowable-engine@d6d39ce1c6 (2026-09-11). Data as JSON: /api/errors/353b5231719763da. Report an issue: GitHub.

Appendix: source

Thrown at modules/flowable-engine/src/main/java/org/flowable/engine/impl/cmd/GetTaskVariableInstancesCmd.java:53

    protected boolean isLocal;

    public GetTaskVariableInstancesCmd(String taskId, Collection<String> variableNames, boolean isLocal) {
        this.taskId = taskId;
        this.variableNames = variableNames;
        this.isLocal = isLocal;
    }

    @Override
    public Map<String, VariableInstance> execute(CommandContext commandContext) {
        if (taskId == null) {
            throw new FlowableIllegalArgumentException("taskId is null");
        }

        ProcessEngineConfigurationImpl processEngineConfiguration = CommandContextUtil.getProcessEngineConfiguration(commandContext);
        TaskEntity task = processEngineConfiguration.getTaskServiceConfiguration().getTaskService().getTask(taskId);

        if (task == null) {
            throw new FlowableObjectNotFoundException("task " + taskId + " doesn't exist", Task.class);
        }

        Map<String, VariableInstance> variables = null;
        if (variableNames == null) {

            if (isLocal) {
                variables = task.getVariableInstancesLocal();
            } else {
                variables = task.getVariableInstances();
            }

        } else {
            if (isLocal) {
                variables = task.getVariableInstancesLocal(variableNames, false);
            } else {
                variables = task.getVariableInstances(variableNames, false);
            }

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