Assume that you use AlwaysOn Availability Groups in an instance of Microsoft SQL Server 2016. When there are too many parallel redo operations on the secondary replica, an access violation might occur.
This problem was fixed in the following cumulative updates for 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. Check out the latest cumulative updates for SQL Server: