On opening ControlPoint application you see error message 'Cannot open database "xcAdmin" requested by the login. The login failed. Login failed for user 'Domain\ServiceAccount'

There are a couple of reasons why this error may occur
1.The xcAdminConnectionString or the xcClient.exe.config has not been configured to point to the SQL server that has the xcAdmin database
2. The Security Admin and or DB creator roles have not been applied to the ControlPoint Service account.
Solution 1
Edit the xcAdminConnectionString and/or the xcClient.exe.config and add the correct SQL server value in the Data Source parameter that holds the xcAdmin database.
Solution 2
Apply permissions in SQL to the ControlPoint Service Account