Cause
Various
Resolution
Most optical drives have an emergency eject slot that is circular. Unbend a paper clip and stick it straight into this small hole on the front of the drive. You will feel a slight resistance as you push. Once it is slightly ejected, pull the drive open manually, and remove your disc.
If you have a Mac, see Apple's guide on this problem on their website at https://support.apple.com/guide/mac-help/eject-a-disk-mac-solutions-mchlp1285/mac.
OUTCOME
Your disc has been manually ejected.