this can happen. They don't have eternal life, especially if not stored carefully (at least: in a dark environment).
If it's a professionally made CD (that uses other technics) it should last at least 50 years. But I assume they burned it themselves.
Better contact the organisator and ask if he has another one for you.
Kees
I purchased a CD containing data at a conference I attended I Dec. 2005.
I have listened to it, and made a copy for a friend. I recently tried to listen again, both on my computer and CD player and it shows up as blank. What could have happened to the data? Thanks, M

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