Symptoms
Assume that you use Microsoft SQL Server 2016 Management Studio (SSMS 2016) to connect to an instance of SQL Server 2012, and you open a maintenance plan that contains a maintenance plan task. In this situation, when you drag a new maintenance plan task from the Toolbox to the plan design surface, an exception may occur.
Resolution
The issue was first fixed in the following cumulative update of 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. We recommend that you download and install the latest cumulative updates for SQL Server:
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.