Symptoms
When you have a named instance of SQL Server 2016, and you try to install Cumulative Update 1 for SQL Server 2016, the installation fails.
Cause
This issue occurs when the named instance is named with a reserved name. For example, if the named instance is named by using any of the following reserved names, this issue occurs:
CON, PRN, AUX, NUL, COM1, COM2, COM3, COM4, COM5, COM6, COM7, COM8, COM9, LPT1, LPT2, LPT3, LPT4, LPT5, LPT6, LPT7, LPT8, or LPT9
Resolution
This update is included in Service Pack 1 for SQL Server 2016.
Each new build for SQL Server 2016 contains all the hotfixes and all the security fixes that were included with the previous build. We recommend that you install the latest build for SQL Server 2016.
Status
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
References
Naming Files, Paths, and Namespaces Learn about the terminology that Microsoft uses to describe software updates.