To resolve this issue, do the following:
Please carry out the following steps:
1) Please also make sure that the SQL Account information is cleared out of the GUI. You can do this by unchecking Windows Authentication and then clearing out the SQL Account information.
2) Revert back to Windows Authentication.
3) Switch to the Services Control panel and navigate to SQL Service
3a) Set the Logon As to be the Account you specified in the Windows Authentication Section
3b) Restart the SQL Service.
Make sure other SQL services installed are also running like SQL Browser.
4) Switch back to the CMN GUI and see if you can set the Configuration
You might also want to refer to the following KB articles as well:
https://support.quest.com/kb/135235
https://support.quest.com/coexistence-manager-for-notes/kb/117345
