Frequent "Connection Lost"

[#1]

We are experiencing frequent connection loss to QlikSense server.  If we work locally (from within the company) there is no problem.

When working from outside, a popup window with the following message appears:

"Connection lost: Make sure that Qlik Sense is running properly.

If your session has timed out due to incativity, refresh to continue working."

We have set the session timeout in QlikSense Server to 30 minutes. But the connection lost happens after a minute.

In the developer console of ChromeBrowser, we can see the following entry:

Error from Engine:" error {target:WebSocket, isTrusted : true, currentTarget : WebSocket,eventPhrase : 2 bubbles : false, cancelable : false, defaultPreveted : false, timestamp :1433922, orignalTarget : WebSocket, explicitOriginalTarget : WebSocket, NONE : 0 }

The connection to wss://xxxxxx.com/resources/app/a4bdfb1b-71f2-42fc-83f2-53f4f7a...?reloadUri=https://xxxx.com-sense-app-a4bdfb1b-..../sheet/UCbAB/state/analysis was interrrupted while the page was loading.

Has someone discovered something similar before? What could be the problem?

[stevedark]

Please see this thread that references the same error message:

https://community.qlik.com/thread/141043‌

You will see my comment on there regarding proxy settings, which is what sorted it for me.

Steve

[phaneendra_kunc]

Steve,

I was not able to understand your comment from your above post.

Adding a manual exclusion for the Sense site in the Advanced settings under the Proxy settings (in the IE, Settings, Connection options) solved the issue.

I have a client who is getting this "Connection lost" message very frequently. And this is not happening to any one else besides this client. And this error is popping up in and around 3-7mins. I have updated my time out settings to 2hrs, but still no use.

Below is the error message i see in the proxy log.

Backend web socket connection Closed for session '28323627-cdf1-457f-8bfe-298fcb2494bd'. App id: '6480f687-b705-495f-a209-72514fd308db. UserAgent: 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_3) AppleWebKit/600.6.3 (KHTML, like Gecko) Version/8.0.6 Safari/600.6.3'

And client is on MAC and using Firefox. I tried simulating the same with my MAC but didn't see connection lost.

Do you have any idea why this might be happening.

[stevedark]

It sounds like a different issue to what I had.  This was on a Windows machine with a web proxy (which I believe caused Sense not to recognise the client as authenticated) and the user could not get on at all - it was not a case of them being able to work for a while and then being disconnected.

It seems strange that the issue only happens to one user.

What type of authentication are you using?

[phaneendra_kunc]

Thanks Steve for the Reply. Yeah that is wired. I am thinking this is something to do with their network or corporate security policy.  Do you know if we have to allow/open certain ports on their end as well?

We are using Windows Authentication.

[stevedark]

There are a few ports that are required.  I don't have them to hand, but you should be able to find them with a quick search.

[#7]

Hello Steve,

For your info, we were also using Windows Authentication.

Further we found out, that the problem occured on one Windows client machine using Firefox v38. When using Chrome on the same Windows machine, the problem was not present. I got told that the problem was not observed with Firefox v39 on the same windows machine.

Conclusion: It looks like our problem was related to Firefox v38 on Windows 8.

[phaneendra_kunc]

Do you mean 443,4244,80, 4248? I though these needs to be opened on server side and not one the client side.

It is wired that Qlikview works fine for this customer and not Sense. I know there is no Webserver with sense and everything is through Websockets. 

[sjb34300]

Did anyone ever find a solution to this?  I'm having a similar issue with one of my users.  They are on a Mac using Chrome.  They receive the "app has closed" error after a few minutes (typically 2 - 5).  No other users have this problem.  I have not been able to duplicate it on my Mac also using Chrome.  Any ideas on how to fix this??

[sjb34300]

We figured out our problem.  We are running Avast anti-virus on our Macs.  Not sure why, but Avast seems to be causing Qlik Sense to lose it's connection after about 2-3 minutes.  Once I added our Qlik Sense URL to the exclusions list in Web Shield, it stayed connected.  We run Avast on our PC's too, so not sure why we don't have this same issue.