flowable/flowable-engine · error · FlowableObjectNotFoundException

task ${taskId} doesn't exist

Error message

task ${taskId} doesn't exist

What it means

HasTaskVariableCmd.execute throws FlowableObjectNotFoundException when the taskId is non-null but no matching task exists in the task service. The engine fetches the task via the task service before evaluating variables; a null result means the variable question cannot be answered for a nonexistent task.

Source

Thrown at modules/flowable-cmmn-engine/src/main/java/org/flowable/cmmn/engine/impl/cmd/HasTaskVariableCmd.java:57

        this.taskId = taskId;
        this.variableName = variableName;
        this.isLocal = isLocal;
    }

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

        CmmnEngineConfiguration cmmnEngineConfiguration = CommandContextUtil.getCmmnEngineConfiguration(commandContext);
        TaskEntity task = cmmnEngineConfiguration.getTaskServiceConfiguration().getTaskService().getTask(taskId);

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

        if (isLocal) {
            hasVariable = task.hasVariableLocal(variableName);
        } else {
            hasVariable = task.hasVariable(variableName);
        }

        return hasVariable;
    }
}

View on GitHub (pinned to d6d39ce1c6)

Solutions

1. Check task existence first via taskService.createTaskQuery().taskId(id).singleResult()
2. For completed tasks use the history service task query/variables APIs
3. Verify the id source and that you target the correct database/schema

Example fix

// before
boolean has = taskService.hasVariable(taskId, "approved");
// after
Task task = taskService.createTaskQuery().taskId(taskId).singleResult();
boolean has = task != null && taskService.hasVariable(taskId, "approved");

Task task = taskService.createTaskQuery().taskId(taskId).singleResult();
if (task == null) {
    // task completed/deleted; fall back to history
}

boolean taskExists(TaskService ts, String id) {
    return id != null && ts.createTaskQuery().taskId(id).singleResult() != null;
}

try {
    return taskService.hasVariable(taskId, variableName);
} catch (FlowableObjectNotFoundException e) {
    log.warn("Task {} not found; checking history", taskId);
    return historyService.createHistoricVariableInstanceQuery()
        .taskId(taskId).variableName(variableName).count() > 0;
}

When it happens

Trigger: Calling hasVariable with a task id of a completed/deleted task, a typo'd id, or an id belonging to another engine/database.

Common situations: Working with historic tasks (query runtime task service instead of history), stale ids cached in the application, hard-coded test ids, or cross-environment database confusion.

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

• Cannot find task with id ${taskId}
• Cannot resume task with id '
• Cannot find case instance for id ${caseInstanceId}
• Cannot find plan item instance for id ${planItemInstanceId}
• taskId is null

AI-assisted analysis of flowable/flowable-engine@d6d39ce1c6 (2026-09-11). Data as JSON: /api/errors/6a894598d9c8f8d8. Report an issue: GitHub.