Consider the following scenario:
You use SQL Server Integration Services (SSIS) with SQL Server 2014 or 2016.
You create two SSIS packages that both run the same child package.
The child package contains a connection string that is specified by an expression.
You execute those two parent packages in parallel.
In this scenario, a race condition that causes an access violation may occur.
This problem was fixed in the following cumulative updates for SQL Server:
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.