I have added 2 albums into Spotify as local files.  Both from the same external harddrive where they've been stored for ages.  Both albums are not on Spotify (or not in the UK at least).

Would like to listen to both on my iPhone.  Have made a playlist for each of the albums on my Macbook, and moved over the tracks.   Now one album works fine, and I have downloaded on my iPhone too - no problems.   The other album is just a nightmare!  The last 2 tracks are the only ones which appear on my iPhone.

Coincendetally, the last 2 tracks appear as greyed out on my Macbook.  They both have the local file icon next to them, wheras the rest of the album does not.  So strange.