Hello guys,

Today I had a problem with a client (PCS7 8.0 SP2). The client was restarted and during Wincc explorer it came up with a warning: Database invalid. After that, project could not be opened, could not be downloaded etc.

After a while, I saw that the Wincc database of the client was in "single user" mode, instead of multi user mode. The logfile sql server 2008 states: Setting database option SINGLE_USER to ON for database CC_xxxxx. After that, the logfile states: SQL server is terminating.

What problem can cause the Wincc database to be set to single user? I now that recently a user was changed (password) in Windows, but nothing else happened. 

I could set it to multi user again, after that I deleted the client project, downloaded and everything was normal again.