Won't Add Songs Anymore

After plugging in the device and adding songs to it on an older windows, it no longer lets me add songs to it on my new computer. Upon plugging in the USB cord and going to My Computer > Panasonic Audio Player, there is only a button that says "Fixed Storage." Once you select that, there is a list of my songs, but you cannot paste without seeing a message popping up saying: '"Song Name" has properties outside device limits, use a media program that can convert...' I tried formating the "Fixted Storage" but it didn't do anything but erase my songs.

I never had this problem prior to using it on my other computer (with older windows). Is my player ruined now?