Symptoms
When you remove a replica from an AlwaysOn availability group, for example, by using the ALTER AVAILABILITY GROUP statement, as follows:
ALTER AVAILABILITY GROUP group_name REMOVE REPLICA ON 'instance_name' [,...n]
You may find "Deadlocked Schedulers" dump files in the error log on the primary replica.
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.