ECMT-The underlying provider failed on Open.

This is an error message that occurs at login. When you attempt to login, this message appears and the login fails.

The first place to go is Event Viewer. This should explain what the issue is. In most cases, it will be database related.

If Event Viewer indicates it is database related, try to view the database in SQL Management Studio. If it is in Recovery Mode, restart the SQL instance service. The database will become available again and login will complete.