Qlik Sense used to work fine and suddenly when accessing the Hub, the web browser is showing "Page Cannot Be Displayed" error message
To troubleshoot this symptom please follow the steps below:
- Check the services in windows and make sure that all Qlik Sense services are running.
- If the Qlik Sense services are running, download the Windows Commands To Retrieve Environment Information batch file, upload it to the Qlik Sense server and run it.
- The batch file above will generate an output text file on the server, save the file then open it in notepad.
- Look at the port information and check if the necessary ports 443, port 80 are open and listening. Please make sure that the firewall is turned off.
- If you can't see any information about ports 443 and 80 open and listening then you will need to look at the Qlik Sense log files.
- See the article How To Collect Qlik Sense Log Files by using the Qlik Sense logs collector .exe file, collect the log files.
- Run the log collector exe file on the server, specify the date range close to the time when the issue happened, select the option that says 'Add windows event logs'.
- The log collector will then run and collect all the Qlik Sense log files and add them into one zip file.
- Download and open the zip file and go to the folder \log\proxy\trace\xxxx_xxx_system_proxy.txt file.
- Look for errors related to connection via port 4242 such as: "https://localhost:4242/ No connection could be made because the target machine actively refused it"
- The error above will indicate that there is something wrong with the repository service not starting properly.
- Go to \log\repository\trace\xxxx_xxx_system_repository.txt file scroll to the bottom of the file and look for errors such as: "established connection failed because connected host has failed to respond"
- The above error indicates that the repository service started but did not run properly due to a timeout. This timeout will be related to the data load process from the repository database into the server memory.
- Qlik Sense comes with a Postgre SQL database. This database contains all the tables that hold all the Qlik Sense system and settings information. One of these tables is called AppObjects.
- Over a long period of time ( years ) the data in these tables get bigger and bigger and eventually the data load process start taking longer and longer ( over the 90 seconds default value ) This will cause the service not to start properly and as a result the port 443 and 80 will not be functional yet.
- To resolve this issue, you will need to cleanup the database and remove all the unnecessary data that was accumulated over long period of time.
- Please download Database Cleanup Script For Qlik Sense Enterprise 2.x And 3.x also see the instructions and steps to perform this cleanup process.
- Once you finish cleaning the database, restart the server and Qlik Sense services will start successfully and very likely that everything will be running as normal and the issue will be fixed.
Once all the above steps are completed, and if the issue is still not resolved or if you need further assistance, please send the following files to Qlik Support via the case portal.
- Issue and test date and time
- The Qlik Sense logs zip file output from the logs collector
- The server stats output text file
- General troubleshooting notes and opinions