Big Sur installation stuck

I wish I saw this thread before trusting the upgrade process. I'm stuck at ~40%... PRam didn't help. Going to look into the mdworker solution from here: https://mrmacintosh.com/macos-upgrade-to-big-sur-failed-stuck-progress-bar-fix-prevention/

Going from Mojave to Big Sur. Mac Pro late 2013. Should have gone to Catalina first I guess. I wonder if I can recover. I've got different partitions and volumes and USBs that are bootable into Mojave, hopefully this can get be back to a functional state without a clean install.

If all the standard recovery options do not work... try the link / fix provided above by @Mentorofmen (older MacBooks will most likely have more than 20K files in those folders):  

 https://mrmacintosh.com/macos-upgrade-to-big-sur-failed-stuck-progress-bar-fix-prevention/

worked for my 2015 MacBook Air and many others...

I too suffer from the Big Sur failure to finish uploading, every time I try, I can’t get it to finish continuing to upload. I’ve tried the ins and outs of ever hard reboot, soft, I even pulled my cord out of the socket, when I slowly put it back in and pushed her button it booted up again and it gets to the last moment before fully finishing and it just stops. I’m sure the other end is happy as hell but I just can’t be satisfied until I finish and she boots up perfectly, fully connected running 500mbps, information flowing fast af, back and forth, in and out, and I know everything is fine when im all over my task and finish and then when I come back to finish another… when everything goes right that time, that’s when I know it’s fixed, sometimes a hard reboot and a yank on the cord will help anyone finish its start up load.. the release of all the anxiety feels sooo good when you get a happy ending. Then I can relax and smoke a cig.

My solution: If you are running any antivirus/malware software, remove it from your system. "Pausing" it, will not work, it has to be removed and then reinstalled after the update is complete. Also, some drivers for some printers can cause this update to fail. Unplug all devices from USB ports. Reboot your system, and then perform the update. Then connect all USB's that you removed and reinstall the antivirus/malware software if you had any. This worked for me, hopefully it will for you as well.

I had the same. Installation got stuck at the final stage (status bar) at 50%. After a while, I've got a blinking question mark with a folder icon...so I did the reboot and the status bar got stuck again at 50%, this time no blinking icon.

I left my MacBook pro (early 2015) for the whole night but the bar didn't move at all Then, what I did:

1. reboot, again the same status stuck
2. NVRAM reset, no improvement
3. PRAM reset, no improvement
4. Safe boot with SHIFT, didn't work at all
5. Recovery mode - interesting here, it went to the INTERNET recovery mode and not the standard one. In the internet recovery mode, I could not find my disk
6. I used Bootcamp to start windows and luckily with paragon software I was able to mount my mac drive and make the backup of the data
7. Next I made again PRAM reset, making sure it was done correctly
8. After this, the Installation was completed immediately and I could see the login screen of Big Sur

Huge relieve! Big Sur works much better on my mac than Catalina. Fans are engaging less, performance is great, and overall very happy with the new system.

My recommendation, make sure you make NVRAM and PRAM reboot correctly, you can eventually run the system in verbose mode and see what is the exact error. Try a few times reboot before you pull the trigger on erasing the data and making a clean install. Time machine backup is a must before trying the update.

good luck!

Had the same issue. What helped me:

1. Turn off your laptop
2. Start your computer and quickly push Command - Option/Alt - R and hold
3. Release when an image of Earth pops up
4. Connect to Wi-Fi (it was disconnected for some reason)
5. Click Reinstall Big Sur

Good luck

Had the same issue on a Macbook Air (2014) and could resolve the issue following the recommendation in the previous comment. Thank you for sharing Pzavora!