For some reason after I made playlists with local files and download them on my PC, everything works. But after I downloaded the playlists on my Laptop which operates on Windows 7 all of the local music files on my original PC became greyed out. And on a much smaller scale, sometimes when I listen to downloaded local files on my phone, sometimes they randomly greyout while the rest of the files are ok, and then I have to do the process mentioned below.
I have no idea how or why, but the only solution I found was to move the music from the Music folder to a different folder and then move them back, afterwards I can re-add my local files and they'll work again.
Is there any other solution to this? Its rather tiresome to have to remove the greyed out files from the playlist and then have to move all of the music files back and forth and then readding them back to the playlist.