When navigating to the Hub, the error "Connection to the Qlik Sense engine failed for unspecified reasons" is displayed, and the error "Error during WebSocket handshake: Unexpected response code: 200" is present in the Developer Console. This issue only occurs when the Hub is accessed from outside the Qlik Sense Server.Environments:
- Qlik Sense Enterprise, All Versions
- Server accessed externally
The client cannot establish a websocket connection to Qlik Sense.
This indicates that the client cannot establish a websocket connection with Qlik Sense. This can be confirmed as described in the article Qlik Sense Websocket Connectivity Tester
. There are several possible solutions:1. Does this occur only in IE, when many browser tabs are open?
See Internet Explorer Supports A Of Six WebSocket Connections2. Is the domain whitelisted?
See Hub Error: Connection to Qlik Sense engine failed for unspecified reasons3. Do you have network appliances between the user and Qlik Sense?
Reach out to your networking team and check:
- Are there network appliances between the client?
- Do those network appliances support websockets? Do you need to explicitly enable websockets?
- Does the client support websockets?
- Are there any aggressive firewall policies in place that are blocking websocket connections?
Please bear in mind that network issues are outside the scope of Technical Support. If you need further assistance, please see How to Contact the Consulting Team?
.4. Also See:Why Does Qlik Sense Use WebSocket?How to troubleshoot web socket issue for Qlik Sense?