Cant Drag & Drop to Inbox

[Mikelap]

Hi, im using 2.5.5804  everytime i rip a CD  i make a data copy on  dvd of my cd's so if something happend i can reinstall them in Musicbee and on a few occasions they came in handy. What i did is drag& drop the file in the INBOX and sent it to the LIBRARY so now i did the same thing again drag & drop in the INBOX but it doesnt let me  what works is when i drag & drop in the playlists but if i drag &drop from playlist to INBOX it works i reinstalled Windows awhile ago along with Musicbee could there be a setting that prevents from using the inbox Thanks