Users are unable to access the Hub with popup message "Internal Server Error" displayed.
Reviewing the Proxy's Trace System_Proxy logs indicates issue with connectivity on port 4900.
Reviewing the Proxy's Trace Audit_Proxy logs indicates issue with websocket connectivity on port 4747.
These ports are used by Qlik Sense Engine and Blocking services. See Sense used Ports
The result of the following commands indicate PIDs that are not of Qlik Sense services origin:netstat -bano | findstr :4900
netstat -bano | findstr :4747
- Qlik Sense Enterprise, all versions
Third party applications such as HFSQL / HyperFile use port 4900 which may cause conflicts.
Note: Only port 4900 is documented to be used by HFSQL publicly.
Investigate if there are any 3rd Party applications recently installed that may be using these ports and uninstall them or change their used ports.