Could not find the Dragon Age Disk. Please insert the disk and try again.

The disc copies have the game have a copy protection that makes it difficult for some DVD drives to read the disc entirely. I've had the issue myself.

I know of two ways to get around it. The first possibility is to get a no-CD crack, but that is a violation of the license agreement. The second method is by uninstalling the game, and registering and downloading the digital version through Origin, which doesn't require a disc.