Qlik Sense Hub Error Cannot create connection or Error Occurred on REST Endpoint Call - Increase WebSocket connections allowed for Internet Explorer

[Bastien_Laugiero]

Internet Explorer supports a maximum of six WebSocket Connections. This can cause connection lost messages or engine connection issues when opening the Qlik Sense Hub.

Connecting to the Qlik Sense Hub is therefore limited to 6 WebSockets by default (six Application/Hub pages).

This is a default limit implemented by Microsoft and be increased or decreased between 2 and 128.

Users may experience the following when reviewing console logs in Dev tools: "... object DOMException... message "SecurityError" ..."

Environment:

Qlik Sense Enterprise on Windows any version
Internet Explorer
Microsoft Edge

In order to change this maximum number of Websocket per connections allowed you need to change a setting on the client computer:

1.  Go to gpedit.msc and navigate under Local Computer Policy > Computer Configuration > Administrative Templates >Windows Components > Internet Explorer > Security Features > AJAX
2.  There is three interesting setting to change:
   • Maximum number of connections per server (HTTP 1.0)
   • Change the maximum number of connections per server (HTTP 1.1)
   • Set the maximum number of WebSocket connections per server
3. You need to enable those settings and change the number of Maximum number of connection 
   
   
   
   
4. Finally, you need to restart your computer

Additional Note: The above settings need to be applied per client. If you have a domain controller you can implement a Group Policy Object with the same setting and apply them globally to your client in your domain.