OK, the problem is solved by Symantec tech support.
Here is the very brief transcript:
spoke to customer
He said that he cannot start DB service
Took remote
DB was starting
Tried to disable it & killed dbsrv12 proc., No go
Ran repiar, no go
Tried to run upgrade.bat, No go
Deleted the conf.
Ran repair and created a new DB
(mistake. repair didn't work. we started the installation file, and in the process it saw that we have DB, program asked to overwrite. after creating new DB the service could start again)
Was able to start the DB process
clients started to check in back
followed TECH1xxxxx
Added the packages..
issue fixed
Closing the case
But there more. You have to navigate between Installation window, TaskManager and Services windows, and timly kill the process and stop and start service.
Could I do this repair again by myself? I'm not sure. You have to know when and what to kill or stop, or change it to Manual.
Yes, it was reinstallation. We couldn't fix it. So, one important thing is to have your serial number for licenses.
I hope it will help to someone.