Did you also change the setting in the ePO database settings page ? (https://localhost:8443/core/config-auth)
n.b. - assumes you are using default port 8443.
This message is normally about a failure to connect to the Sql server.
Ref: McAfee support articles KB69850, KB66166
As i'm leaving for weekend now, i will try thiy on monday.
Thx for your fast response.
after "fixing" the setting in ePO database settings page it works fine.