In this post, you’ll learn more about the Error ERROR_FLT_POST_OPERATION_CLEANUP – 0x801F0009 that is returned when working with the COM-based APIs in Win32
Win32 COM Error
ERROR_FLT_POST_OPERATION_CLEANUP – 0x801F0009
Win32 COM Error Error Description
The filter must cleanup any operation specific context at this time because it is being removed from the system before the operation is completed by the lower drivers.