Connection to the qlik sense engine failed for unspecified reasons when connecting to the Hub only
Article Number: 000050450 | Last Modified: 2019/07/18
Users start seeing the error Connection to Engine Failed for Unspecified Reasons when accessing the hub.
When this starts to occur, it happens consistently until the entire node is restarted, but users accessing applications directly (using a browser bookmark or shared link) are unaffected.
Additional checks into the environment reveal no normal websocket problems
Qlik Sense September 2017
Qlik Sense November 2017
Qlik Sense April 2017
The error message is misleading, it indicates that a websocket connection failed, and when accessing the hub the websocket is created against the repository service on the engine node.
This endpoint can fail in some circumstances, leading to the all future websocket establishment failing until the service is restarted, and a misleading error message about the engine.
This is caused by a product defect (QLIK-86030) in the repository service which was fixed in Qlik Sense April 2018