sd card freezing the unit

I recently purchased a Sansa Clip Zip.  Have added songs to the internal storage and they work fine.  I added roughly 2000 songs to a 32gb sd card and when I insert the card it takes over an hour to “Refreshing your media”.  Sometines it freezes and I have to try again.  When it does work and I attempt to play off of the sd card the unit freezes and shuts down.  If there is a folder or file that is causing the hang up how would I go by detecting it?  Thanks.

SanDisk’s players are tag-based. I would download the free program, MP3Tag and open your files in it to see if there is any one (or more) that has strange, foreign characters in any of the fields, exceptionally large album art embedded, delete anything in the Comments field, an ensure all are in the format ID3v2.3 ISO 8859-1.

Thank you I will try that.

A card should only be added or removed when the player is off.

Sandisk players sometimes have issues with cards faster than class 4.

Thank you greatly for taking the time for some advice.  It turned out that it was a bad Micro sd card.  I ordered a generic one from ebay.  Lesson learned.  It works fine with a new card.