1. Check free disk space
macOS major updates need 25–45 GB free during install (temporary scratch space). System Settings → General → Storage. If your free space is under 25GB, the installer can stall.
Free up space: Trash, Downloads folder, old iOS backups in ~/Library/Application Support/MobileSync, large videos. Pakistani users often have hundreds of GB of WhatsApp video; clear it.
2. Verify your internet connection
macOS installer needs sustained internet for 1–4 hours during install. A flaky Pakistani PTCL connection that drops every 20 minutes will cause partial download → stalled install.
Use a tethered phone (mobile data with full bars) as backup if your home internet is unreliable.
3. Boot into Recovery Mode and reinstall
If the Mac is stuck on the Apple logo or progress bar after 1+ hour: force shutdown (hold power 10s), then boot into Recovery (Cmd+R on Intel, hold power on Apple Silicon then choose Options).
From Recovery: Disk Utility → First Aid your main volume → reboot → try the update again. Or 'Reinstall macOS' (preserves your data).
4. When the SSD itself is failing
If repeated reinstall attempts all stall at the same percentage, the SSD has bad blocks. On Apple Silicon Macs the SSD is soldered; the fix is board-level repair (NAND replacement) at PKR 25,000–50,000.