This from Chepal in Germany, regarding rebuilding BPAV folder structure from orphaned files:
in clip_browser
_file_import_choose your mp4s and they will appear in the top left window
_in the bottom left window direct to the area you want to be in and create a new folder_select it
_drag your mp4s from the top window to the bottom
_look at the folder on your hard drive and you would find it has created
new folder_BPAV_and all the stuff it needs.