[Beemer]

It is deleting solely from the import source folder; it is not going to look in all folders to see if they also have a copy.

This is typically used as follows:-

1. download or transfer one or more songs (ideally to an "empty" folder)
   
2. import the songs into MS using the "delete after importing" option
   
3. it does what it says on the tin and the import folder should be as it was before you downloaded any songs (makes it easy to see what is needed for future imports)
   

You probably only want to do this when you have selected "let MobileSheets Manage My Files" (in the Storage options).

Don't enable "delete after importing" if you are importing from your main "source" folder!

Geoff

Geoff,
Thanks for your answer which is assuring.  I used to let MS work directly with my source files as it appeared quicker to display them but mainly to avoid duplication of a large number of files in a 32GB maximum tablet.  I now import from my NAS so have changed to  "let MobileSheets Manage My Files"