flowable/flowable-engine · error · FlowableObjectNotFoundException

task

Error message

task 

What it means

After validating inputs, GetTaskDataObjectCmd loads the task via TaskService.getTask(taskId). If no task exists for that id it throws FlowableObjectNotFoundException("task <id> doesn't exist", Task.class), meaning the taskId is well-formed but references no live task.

Source

Thrown at modules/flowable-engine/src/main/java/org/flowable/engine/impl/cmd/GetTaskDataObjectCmd.java:73

        this.variableName = variableName;
        this.locale = locale;
        this.withLocalizationFallback = withLocalizationFallback;
    }

    @Override
    public DataObject execute(CommandContext commandContext) {
        if (taskId == null) {
            throw new FlowableIllegalArgumentException("taskId is null");
        }
        if (variableName == null) {
            throw new FlowableIllegalArgumentException("variableName 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);
        }

        DataObject dataObject = null;
        VariableInstance variableEntity = task.getVariableInstance(variableName, false);

        String localizedName = null;
        String localizedDescription = null;

        if (variableEntity != null) {
            ExecutionEntity executionEntity = CommandContextUtil.getExecutionEntityManager(commandContext).findById(variableEntity.getExecutionId());
            while (!executionEntity.isScope()) {
                executionEntity = executionEntity.getParent();
            }

            BpmnModel bpmnModel = ProcessDefinitionUtil.getBpmnModel(executionEntity.getProcessDefinitionId());
            ValuedDataObject foundDataObject = null;
            if (executionEntity.getParentId() == null) {
                for (ValuedDataObject dataObjectDefinition : bpmnModel.getMainProcess().getDataObjects()) {

View on GitHub (pinned to d6d39ce1c6)

Solutions

1. Verify the taskId is correct and exists via taskService.createTaskQuery().taskId(id).singleResult() before reading variables
2. Handle FlowableObjectNotFoundException in the caller and treat it as 'task gone' (e.g. re-fetch or inform the user)
3. Check you are connected to the same process engine/database that owns the task
4. If the task may legitimately disappear, catch the exception instead of letting it propagate

Example fix

// before
DataObject d = taskService.getDataObject(taskId, variableName); // throws if task gone
// after
Task task = taskService.createTaskQuery().taskId(taskId).singleResult();
if (task != null) {
    DataObject d = taskService.getDataObject(taskId, variableName);
}

Task task = taskService.createTaskQuery().taskId(taskId).singleResult();
boolean exists = task != null;

boolean taskExists(String taskId) {
    return taskId != null
        && taskService.createTaskQuery().taskId(taskId).count() > 0;
}

try {
    DataObject d = taskService.getDataObject(taskId, variableName);
} catch (FlowableObjectNotFoundException e) {
    // task deleted/completed; treat as empty result
    d = null;
}

When it happens

Trigger: Calling taskService.getDataObject(taskId, variableName) with a taskId that was deleted, never existed, belongs to a different engine/database, or refers to a completed task removed by history cleanup.

Common situations: Stale task ids cached by the caller; task completed and deleted between lookup and variable read; querying against a test database while using ids from another environment; tenant/db mismatch in multi-engine setups.

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
• No task found for taskId '
• Cannot resume task with id '
• Cannot find task with id ${taskId}
• case instance doesn't exist

AI-assisted analysis of flowable/flowable-engine@d6d39ce1c6 (2026-09-11). Data as JSON: /api/errors/57a0ad852c4073fb. Report an issue: GitHub.