I have a Sony Video Walkman NWZ-A818 that I bought a few years back. It hasn't seen a great deal of use in the last year or so and I'm afraid I've forgotten something I did regarding a setting early on because I have lost my drag and drop functionality to or from the Walkman.
I have it set up to work with a program called WalkmanMTP so that I can create playlists and I believe that something I did to get the Walkman to cooperate with this program is the reason I lost drag and drop but I can't think what it could be.
I've run quite a few searches to no avail. Any help is appreciated.