FIX: Error 15665 when you call sp_set_session_context repeatedly with null key value in SQL Server 2016 and 2017

Applies to: SQL Server 2016 Service Pack 1SQL Server 2016 DeveloperSQL Server 2016 Enterprise

Symptoms


Assume that you are using Microsoft SQL Server 2016 and 2017. When you run the sp_set_session_context stored procedure repeatedly (for example, more than 10 times) to set the KEY value parameter with a NULL value, you may receive an error message that resembles the following:

Msg 15665, Level 16, State 1, Procedure sp_set_session_context, Line LineNumber [Batch Start Line LineNumber ]
The value was not set for key 'KeyName' because the total size of keys and values in the session context would exceed the 1 MB limit.

Resolution


This issue is fixed in the following cumulative update for SQL Server:

       Cumulative Update 6 for SQL Server 2017 

       Cumulative update 8 for SQL Server 2016 SP1

Status


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

References


Learn about the terminology that Microsoft uses to describe software updates.