Update Endpoint 12.1

Hello,

I did update SEPM 12.1 because Symantec send me an e-mail. I did backup the database and then installed. Now I get a wizard which tells me that it's not able to restore the port setting. Then the wizard asks if I want to use default settings. I click yes. But then the default setting are not ok.  I get: The server port you chose is not the port used by the database.

I tried 8445, 2638 and 2639.

I know nothing about ports or technical stuff. Please help!