Accessing or navigating through the Qlik Sense Hub may show Engine related error messages.
The messages may vary and are not limited to: An error occurred No available Qlik Sense Engine Was found. Refresh your browser or contact your system administrator.
Connection to the Qlik Sense Engine failed for unspecified reasons. Refresh your browser or contact your system administrator
No Engine server is available for the following app app:_hubNo broker service availableAn error has occurred
This article provided guidance on how to troubleshoot these issues, as well commonly known solutions.Environment:
Qlik Sense any version
The above errors indicate communication problems between the Qlik Sense Proxy
service, the Qlik Sense Engine
service, and the Qlik Sense Dispatcher
service (also known as the Broker
Are the Qlik Sense services running?
- Connect to the server(s) supposed to run the Qlik Sense Engine Service to find out whether the service is up and running.
- Verify the same for the Dispatcher Service
Suggested Action: Try to restart those services
Can the Engine(s) be reached by the Management Service (QMC)?
- Open QMC and in Configure System go to Engines and make sure it/they are marked as running
Suggested Action: Try to restart those services and verify that all architecture requirements are met (see next step).
- See the Qlik Sense online documentation. Port allocations may vary depending on the deployment version. Select the correct version.
- Verify that an engine is attached to the Virtual Proxy that is serving the Qlik Sense Hub.
- Is the Qlik Sense Proxy configured with the correct WebSocket host white list?
- Is the WebSocket protocol allowed between the client machine and the Qlik Sense Engine Server through the network?
Log file analysis
- Gather the Qlik Sense log files using the Qlik Sense log collector. See How To Collect Qlik Sense Log Files
- Alternatively, the currently active Qlik Sense log files are by default stored in C:\Programdata\Qlik\Sense\Log (only applicable if file logging is enabled!)
- For more details on how the Qlik Sense file logging works, and where archived logs are stored, see How logging works in Qlik Sense.
Suggested actions: Review the logs with a timestamp of the encountered issue to find related error messages.
Search the available Qlik knowledge bases
Using the symptom and error messages found in the Qlik Sense log files, search the available knowledge bases
Common symptoms and resolutions
Qlik Sense 3.0 and later- "No Engine" Message In The HubQlik Sense Hub: "?????????? _??? hub" message appears
Error Message "app: __hub" When Accessing Qlik Sense Hub Or Qlik Sense DesktopQlik Sense Repository and/or Proxy unable to perform operation due to buffer spaceHub Error: Connection to Qlik Sense engine failed for unspecified reasonsConnection to the Qlik Sense engine failed for unspecified reasons randomly on the hubOpen Hub With Error "The load balancing module did not return any engine service for the following app:_hub"
Log a Support Ticket
If the above did not help resolve the issue, or further investigation is required, please reach out to Qlik Support.
- Collect the Qlik Sense logs How To Collect Qlik Sense Log Files
- Make sure that the Logging Level set in the QMC -> Engine -> Logging is set to INFO and DEBUG. We recommend to use DEBUG mode only for troubleshooting purpose. Under a loaded environment this mode can created instabilities.
- Include at least one timestamp and UserID of when the issue was seen
- Include detailed symptoms of the problem, such as an error message, problem experienced by the end user or administrator, and a screen capture of the error message