FIX: Cannot connect to a named instance after failover on a mirror server in SQL Server 2014 or 2016

Applies to: SQL Server 2016 DeveloperSQL Server 2016 EnterpriseSQL Server 2016 Enterprise Core


Consider the following scenario:

  • You use the Microsoft ODBC Driver for SQL Server and the Microsoft SQL Server Native Client 11.0 that is installed when you install SQL Server 2014 or 2016.
  • You connect to a named instance of SQL Server 2014 or 2016 that is running database mirroring.
  • Failover of the named instance occurs from the principal server to the mirror server.
In this scenario, when you hide the named instance or you stop using the SQL Server Browser service, you cannot connect to the named instance on the mirror server.


To resolve this issue, install the following cumulative updateand ODBC driver for your version of SQL Server.Note Although the driver is included in the cumulative updates forSQL Server 2014, you must install the driver separately for all versions.

Cumulative update

ODBC driver


To work around this issue, restart the SQL Server Browser service.


Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.


Learn about the terminology Microsoft uses to describe software updates.