When you query the sys.dm_db_file_space_usage Dynamic Management Views (DMV) while the secondary replica has started transitioning its role to primary, you encounter the following assertion exception:
Location: purecall.cpp:LineNumber, Expression: !"purecall", Description: Pure virtual function call
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
This issue is fixed in the following cumulative updates for SQL Server:
About 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: