Sansa Clip has 1.5 Gig books on it but suddenly I can' see them

My Sansa clip v01.2.15A with 4G memory, has suddenly lost the ability to ‘see’ those books on it.  I shows 2 chapters of one book .  nothing else is anywhere to be seen.

USB mode is MSC.  I’ve tried auto detect and MTP but neither change anything.

Have  used the 15 second power reset several times with no result.  When attached to my computer it shows that the memory is half full.

I’ve listened to many books on t his since buying .  I know they are on there but just cannot be seen or selected. 

Any suggestions?  Thanks

What format are these ? Are they properly tagged? Do they show up on the player when you go to music>folders?

they were all in audiobooks and were easily seen and listened to.   Some in folders and some just the mp3 files for the book. Now they are invisible to Sansa Clip itself and when hooked up to my computer.  

hmmmmmmm…

Without additional information, I can’t say what is going on. Are these all mp3 files? If you have copies of these on your pc, you could format the player using the player’s menu, then copy the files to the player again using Windows Explorer copy and paste.

Some people who sync their player have reported files mysteriously disappearing. I never sync my players, and transfer files to them using copy and paste. Before I copy them to the player, I use mp3Tag to correct any mistakes in the tags, and make sure the tags are ID3 v2.3 ISO 8859-1 which the player needs.