Assume that you set up a database mirroring session in SQL Server 2012,2014 or 2016. You add a witness to support automatic failover. In a rare situation, the mirroring session may stop, and then the data is no longer synchronized. Additionally, an automatic failover doesn’t occur as expected.
This issue is fixed in the following cumulative updates for SQL Server:
Each new cumulative update for SQL Server contains all the hotfixes and all the security fixes that were included with the previous cumulative update. Check out the latest cumulative updates for SQL Server:
To work around this issue, resume the mirroring session. To do this, type each of the following Transact-SQL statements, and then press Enter after each statement:
ALTER DATABASE database_name SET PARTNER SUSPEND
ALTER DATABASE database_name SET PARTNER RESUME
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
Learn about the terminology that Microsoft uses to describe software updates.