In this post, you’ll learn more about the Error CERTSRV_E_NO_DB_SESSIONS – 0x8009400F that is returned when working with the COM-based APIs in Win32
Win32 COM Error
CERTSRV_E_NO_DB_SESSIONS – 0x8009400F
Win32 COM Error Error Description
An attempt was made to open a Certification Authority database session, but there are already too many active sessions. The server may need to be configured to allow additional sessions.