Connection engine failed, for 1 app only

[ramzi-manoubi]

Hi,

I'm experiencing something strange with one of our apps.

When I try to save the load script, I get the error: "Connection to the Qlik Sense engine failed for unspecified reasons."

After a refresh, the app is saved.

Also when using this app, I get this error. Takes only a few seconds for the message to prompt.

I have a scheduled task for the reload, which always gets the status "Failed".

The app did reload though. If I look in the log, everything looks normal.

Manually reloading the app also works correctly, without errors.

Anybody a clue why it fails, and only for this app? I have another app which connects to an other database, with a very similar loadscript, for which I get no errors.

Duplicating the app, exporting en reloading the app produces apps with the same problems.

I also tried already white listing the domain as suggested in other topics.

The app was created over a year ago and was always used with Qlik Sense Desktop. It's only now, we want to install it on the server.

Any ideas? My knowledge of the server software is very limited. Any help is very welcome. Thank you.

[ramzi-manoubi]

Added the app, without data, without sheets. When I import this app to the server, change the load script and try to save, I get the error.

At this point I'm assuming it's a bug.

[NZFei · Accepted solution]

From my experience, if you have this error when accessing the server hub, that is because the server name has not been added into the white list.

If this only happens to one app,  I would be interested to know which Sense version you are using.

Both the versions for June 2017 patch 2 and the September 2017 say that they have fixed this bug:

[ramzi-manoubi]

Thank you for your interest in this topic.

Yes, we're using an old version. That'll probably be the reason.

I'll discuss this with our IT manager.

[ramzi-manoubi]

Upgrading the server solved indeed the issue. Thank you.