Here is what you should do try to troubleshoot the issue:

1. Check if the DVD/Blu-ray is compatible with the computer.
2. Verify that you have DVD/Blu-ray capability.
3. Install available hardware and software updates.
4. Check if the DVD/Blu-ray is clean and free of scratches.
5. Verify that the correct DVD/Blu-ray player is installed.
6. Clean the disc with a soft, lint-free cloth.
7. Check if DVD/Blu-ray drive is properly connected.
8. Ensure correct disc region setting.
9. Remove and re-seat the DVD/Blu-ray drive.