We are really getting crazy for this:
Suddenly when trying to connect to Management Studio with trusted connection, our db server is returning this error :
Login failed for user ''. The user is not associated with a trusted SQL Server connection. [CLIENT: X.X.X.X]
In the sql server log and in the event viewer this error is always associated with this one:
SSPI handshake failed with error code 0x8009030c while establishing a connection with integrated security; the connection has been closed. [CLIENT: X.X.X.X]
We don't own the sa password (the guy who installed the server says he didn't input any password for sa, is that possible?), blank password doesn't work.
We have access to the phisical computer with an administrator account. The very same administrator account has been used to access SQL using trusted connection until friday and now suddenly is returning this error, apparently with no logical reason.
I have been trying in any possible way using a remote connection with terminal service:
1. tried connecting with oSql -E -S <servername> (same result)
2. tried to add the administrator account to every possible SQL SERVER group on the machine
3. tried connecting using SQL server authentication using the administrator username e password
The computer is not even in a domain, it's the only machine in a workgroup.
Any suggestion to find a way out other than spending at least 99 euros to open a microsoft incident with technical support is welcome...