If you can access the microSD card from Windows, right-click on it and go to Properties/Tools/Error-Checking.That might fix a bad file.
Otherwise, you might try exploring the SD card and looking at some of the files you have added most recently. The free program mp3tag is good for fixing problems.
Install mp3tag. When you install, let it add itself to context menus (an option while installing).
Open mp3tag and in Tools/Options/Tags/Mpeg make the Write option ID3v2.3 ISO-8859-1. That’s what the Fuze likes.
Go to the folder or files most recently added. . Right click, and just below Search… you should see mp3tag. Click it, mp3tag will list the files.Highlight them all, make sure there’s correct information in Title, Artist, Album and no weird characters. Blank out Comments–you can’t read them on the Fuze anyway. Save. That will make them all ID3v2.3 ISO-8859-1 and the Sansa should read them quite happily.
Besides big comments–some people try to stuff whole books in there–another thing that can stump the Fuze is large imbedded images in the files. You only need one album cover in the folder–not the album cover in every song. If changing the tag format and blanking out Comments doesn’t help, then go back to the album folder with mp3 tag and under View choose Extended Tags. Then you can see if the art is imbedded in the tag. The X symbol to the right of the displayed cover lets mp3tag delete it from the file, extract it and call it folder.jpg–the image the Fuze will use for the cover anyway.
Before I put anything on the Fuze, I run it through mp3tag–either using the Auto-Numbering Wizard under Tools, with leading zeroes (numbering tracks 01, 02, etc. the way the Fuze prefers) or just using Save to change it to ID3v2.3 ISO-8859-1. Takes 5 seconds,
