Server is not reachable or still initializing, please refresh the page in a few seconds

Product:
Cognos Controller Web 10.4.2
Microsoft Windows 2019 server

Issue:

After applied a DNS alias to the Cognos Controller server, the users can not login to the Controller Web.

They get a error like Server is not reachable or still initializing, please refresh the page in a few seconds

Solution:

You must update the D:\Program\ibm\cognos\ccr_64\frontend\config.js file with the URL the end user will use to access Cognos Controller Web.

If you change it from a server-name to a DNS alias, then open config.js in notepad++

 //Details for Controller UI service 
"expressJs": {
"host": "cognoscontroller.domain.com", //interface used by Controller Web UI Service
"port": "9080", //port used by Controller Web UI Service
"options": {

Change the interface value to your DNS alias. The controller web backend connection at line 14 can be left with the server host name.

Save the file.

Restart the 3 Controller web services.

More Information:

https://www.ibm.com/support/pages/troubleshooting-server-not-reachable-or-still-initializing-please-refresh-page-few-seconds-error-launching-controller-web