QcExpress is authenticating user via the natific SSO and to do this it needs to start a temporary local web server on one of these ports:

  • 45656
  • 42684
  • 48621
  • 54213


Please note that these ports should not be configured on a firewall, these are for local communication only, from your web browser to QcExpress.


If QcExpress is not able to start the temporary local web server it will display this error message:



The following problems can prevent QcExpress from initiating the login process:

  • Strict security policy on the computer: the currently logged in user cannot start a server using any local port.
  • An anti-virus or anti-malware software is blocking QcExpress from starting a server using any local port.


Please involve your IT department and based on the above, do the following:

  • Whitelist QcExpress in the security policy or allow one of the above ports regardless of which application tries to use it.
  • Whitelist QcExpress in the anti-virus or anti-malware software so it allows QcExpress to start the local web server.


If you think you have done the above suggested steps yet you are still having issues, please contact [email protected] and send us the QcExpress logs from %AppData%/QcExpress/logs .