In this post, you’ll learn more about the Error ERROR_VOLMGR_PLEX_LAST_ACTIVE – 0xC038003B that is returned when working with the COM-based APIs in Win32
Win32 COM Error
ERROR_VOLMGR_PLEX_LAST_ACTIVE – 0xC038003B
Win32 COM Error Error Description
The specified plex is the last active plex in the volume. The plex cannot be removed or else the volume will go offline.