When you say "drug the file to my favorites", what folder location do you mean exactly (in Windows, MusicBee, etc)--did you actually add it to your MB Library? Did you rename the file using MusicBee's edit tools, or using Windows? Can you find the file on your PC doing a search in File Explorer/Windows Explorer? In MusicBee, do Tools/Advanced/Rescan All Files--does it turn up afterwards?
Please also indicate what version of MusicBee you are using (Help/About).