Test Known-Good Disc: Borrow a working game. If it fails → Drive laser/sled.
Drive Replacement: $30–60 (eBay) + Torx T8/T10. Tutorial: iFixit "Xbox One/Series X Drive Swap." Must marry new drive to motherboard (PC + Xbox OSU1) or swap PCB.
2. Digital Games Only? → Storage / License / Corruption
Free Space: Need 20%+ free. Manage → Uninstall junk.