'Disc Error' message in 2002 Prius. Causes and possible further complications?

Well, I have looked through my 2002 Prius's owners manual, and I could not find anything relating to what had just happened, so I wanted to check in on here before getting an appointment set up at a dealership so that I could possibly at least know a potential cause for this problem.

What happened is that when I was letting my Prius warm up this afternoon before I drove it, I turned the music player on to select one of the six CDs that I had inside it. I should note that the CD player was working fine only four hours before that point. While I was waiting, the player sounded as though it was straining, or something to that effect. After around ten seconds of the player trying to play a CD, my car beeped and flashed the message "Disc Error" on the display; since that message first appeared, I have now not only been unable to play any of the six discs, but the player also will not let me eject the discs.

In addition to asking if anyone might know a potential cause of this problem (one thing that I can attest is that all of the discs were clean when I put them into the player), I would like to know if this is an issue that could potentially cause more significant problems if it is not dealt with quickly. I should also note that my Prius has not displayed any messages other than the "Disc Error" message since the issue first arose.