iTunes refuses to import playlists. Any idea why? Yes I have the latest version. The error message in question says:
"The file "[playlist name]" cannot be an imported An unknown error occurred (-50)."

Copy "iTunes 4 Music Library" and "iTunes Music Library.xml" out of your Music/iTunes folder. Put them on your Desktop.

Delete those two files from your Music/iTunes folder. [b]Do not delete the ones on the desktop, only delete the ones in the Music/iTunes folder. Now the only thing in there will be your "iTunes Music" folder (unless you keep that somewhere else, of course).

Start iTunes. It opens up empty. Now quit iTunes. Notice it has created new, empty ‘iTunes 4 Music Library’ and ‘iTunes Music Library.xml’ files.

Delete those new files. Now on your desktop select the two files you copied there (iTunes 4 Music Library and iTunes Music Library.xml) and cut them and paste them back into your Music/iTunes folder.

Now open iTunes and try to import a playlist.

------------------------------------------------

If that doesn't work try and uninstall iTunes from Add\Remove programs (Start > Control Panel > Add\Remove programs > iTunes > Change\Remove > Follow uninstaller). Then restart your computer and download and install it again.

I've tried what you said (including uninstalling and re-installing) but the error message keeps coming up. Any idea what might be causing this?