Connection to the Qlik Sense engine failed for unspecified reasons
I have one single user who is not able to access any apps due to the "Connection to the Qlik Sense engine failed for unspecified reasons" error. He is able to log in successfully, but as soon as he lands on the hub page he gets this message and is unable to proceed. This is the only user in our deployment that has ever reported this issue. I have not been able to replicate the error circumstances myself. The user works/lives remote so it's been a little challenging to troubleshoot this, but I have read and tried suggestions from several other posts on the issue.
The problem is I'm not finding anyone else who has experienced this issue for just one user only. Does anyone have any ideas for me?
I'm on Sense Feb 2019, I have the server address white listed in QMC, and all recommended ports open in my firewall rules. The user is on Windows 7/Google Chrome.
Consider changing their location using an RDP session to a known working browser on another machine. From there you can rule out the user itself and divide an conquer what variables remain (VPN, Browser, Proxy settings in a browser, etc...).
The development tools (network and console) on the browser could also lead to clues as to why it is failing.
Re: Connection to the Qlik Sense engine failed for unspecified reasons
If HTTP works for your iPhone, this would be correct for a scenario where the Central Node does not contain the Apple Certified certificates (configured in the QMC proxy security thumbprint). One's IT support should be contacted to add these Apple Certified certificates in the central node.
A good way to troubleshoot the connection is to use HTTP vs HTTPS, if HTTP works it is likely lack of or wrong certificates.