Seqouia 15.1 software update error

There are factors:

Some which are beyond your control and those with are totally under your control

Slow wifi connection

Too many other people downloading at the same time and Apple  Servers are overloaded

Software on the computer interfering with the download process including AntiVirus Software

Notation: Disabling the AV Software may or may not solve the issue.

Removal of the AV Software may increase the chances of the download to perform as expected.

Running behind a VPN which may increase Packet losses or corruption of the download 

If via wifi  & too many Other devices using the wifi at the same time reducing the Bandwidth to your computer. 

Best Results are via Ethernet Cable to Router

Restart in Safe Mode. This will perform a Disk Repair, clear cache files and only load Apple Software, extensions and fonts. The boot up will be slow and can take some time - Normal 

Try Again using the Software Update Applet in System Preferences / Setting 

Worst case - Restart in Recovery Mode and choose Reinstall macOS. 

This in theory will pull the latest version of macOS this computer qualifies to run 

This is a pain, but I'm certain it will work. It worked on ALL of my 2018 Macbook Pro's, and I have lots of those machines:

1) IMPORTANT: make a full Time Machine B/U of your Mac

2) Restart your Mac in Recovery Mode using ONLY the key combo: Option+Command+R, hold these keys down until the Apple shows up asking which WiFi network you want to use

3)Select "Reinstall MacOS Sequoia", and follow the prompts to do so. DON'T WORRY! Using this restart key combination will install the LATEST MacOS your machine is compatible with, and it will NOT delete or overwrite your applications or your data!! (But you have the Time Machine B/U anyway) If you end up with Sequoia 15.0.2, then your machine can't handle 15.1.1. (HIGHLY Unlikely) Be prepared for this to take literally hours (all day or overnight), depending on the throughput speed of your WiFi.

4) Once finished, go to the Apple>about this Mac and check the MacOS installed. It should now be 15.1.1. For some reason downloading and installing from Recovery Mode work where using the Software Update option in Setting does not.

Hope this helps!

I was able to fix the issue by reviving my MacBook Pro with another MacBook Pro. Afterwards, I was able to perform the update to 15.1.

Make sure to revive, not restore:

How to revive or restore Mac firmware - Apple Support

I found a solution that worked for me based on something I saw on reddit. It recommended turning off the Find Me on the iCloud account then updating, which worked on my MacBook Pro 16-inch 2019.

Turning Find Me back on did bring up the following message though "Some configurations, such as a software or hardware RAID, do not support a recovery partition and can’t be used with Find My Mac." But I ran First Aid in the Disk Utility and then I was able to turn Find My back on.

All is now right with the world (until the next update).

Same issue here

2019 Macbook Pro 16", Intel Core i9

I found uninstalling Bitdefender Antivirus and VPN fixed the issue, I'm not sure whether it was the antivirus, VPN, or both, but completely uninstalling Bitdefender allowed the installation to continue

Good morning,

same here on Intel Macbook Pro 16" 2019. I think, I solved by switching the content caching in system setting on/off.

Look at System Settings -> General -> Sharing -> Content Caching.

Found the trick on other forum, It sounds that the switch on/off deletes a download cache, if one of the last try of an update fails.

I had the same issue with this upgrade as others reported on my MacBook Pro 16" 2019, Intel core. I tried most of the options in this thread first but they didn't work. Not sure if it was persistence but I got 15.1 to install eventually by:

1. Reinstalling existing MacOS Sequoia 15.0.1 in Recovery Mode. The install ended after reaching the final minute with a strange fan sound and a notification that the system had been restarted because of an error. However everything looked fine when I went back in
2. I then re-started in Safe Mode and installed 15.1 in the normal way using System Settings>General>Software Update. The update still got stuck at "30 minutes remaining" and the fan whirred away but this time it made it through the install, kicked off the re-start and I got any number of black screens with apple logos and progress bars before getting back in with 15.1 installed

Definitely recommend taking a full backup before trying any of this as there were some odd noises at the end of that 15.0.1 re-install.

i finally got my 2018 MacBook Pro (intel chipset) updated to 15.1 from 15.0.1 after several failed attempts to update via normal update procedure. I used the preboot ‘Option’ menu, which included a “Re-Install Sequoia” choice. I did a full backup before doing this. It took about 3 hours to do this.

I think this puts me on notice to start saving to buy a replacement “soon” for my nearly 7 year old MacBook Pro.

I have a Macbook Pro of 2020 with processor 1.4 GHz Quad-Core Intel Core i5 and I had the same update issue. After various attempts, I switched the sharing cache on and off and thereafter did a safe reboot and the Seqouia update installed correctly after a preparation time of some 30 minutes. The installation took about 30 minutes also, so be patient. I suspect that the safe reboot did the trick. I hope this helps some of you to get over the issue. Success.

Worst of worst cases

Terminal command below

softwareupdate --fetch-full-installer --full-installer-version 15.1

Manually download the FULL Version

Installation failed four times yesterday, then turned off Mac OS firewall and it works on 2019 MB Pro 16“ intel.

I finally decided to resort to internet recovery. My files are in the cloud anyway. So erased my disk with the disk utility, then installed 15.1 from internet recovery. That worked! But now Xcode is giving me troubles.

All this doesn’t bode well for any future Sequoia updates, fingers crossed …

I left it for a few days, and today it was able to install the 15.1 update.

Same here. 2018 MacBook Pro 13inch four thunderbolts 3 ports. 2.3 GHZ quad core intel core i5. Tried safe mode, same error. Tried recovery mode and installing sequoia again, same error. Contacted apple and they have no idea how to fix it besides erasing my Mac and starting from scratch. Any ideas? I already tried turning off “find my Mac” and cache sharing…. At my wits end since nothing seems to be working.