macOS sequoia 15.2 update Mac Pro 2019 failed

OWC Thunderbay 4 drives not loading after 15.2 update. I've never encountered issues prior. All drives are APFS formatted. They load fine on MacBook Pro with Mac OS 15.1.

Anyone else with OWC Thunderbays might want to follow this advice which I came upon after the fact...from OWC blog: "When you upgrade to macOS 15.2, I suggested you complete the upgrade while the enclosure is disconnected from your Mac and then reconnect it once the upgrade has completed. This will ensure that your Mac will run correctly during the upgrade process."

Confirmed with OWC ThunderBay 6 / Thunderbolt 3 with APFS AppleRAID0

https://eshop.macsales.com/blog/96473-macos-15-sequoia-2019-mac-pro/

This is what I've also found to be the issue. Leave thunderbay off then turn them on after boot. All my drives load fine and worked all day today.

I had it hang once when I tried to restart hoping that would load the drives but had to force restart with power button, booted fine the 3x after that happened with the Thunderbay on. No drives loaded. Just found out my iPhone wont connect to Mac Pro...this must be a Mac OS 15.2 bug.

I do also get immediately after booting back from the 15.2 upgrade the same screen, but disconnecting everything made the 2019 Mac Pro to boot. But I can confirm that even a Sabrent16 ports USB 3.1 HUB (from Amazon) and OWC Thunderbolt 3 Dock do not work anymore after upgrading. No matter where you connect it (USB or TB).

This is a real problem if you have many external device to connect to the Mac Pro.

My 2019 macbook pro running 15.1.1 also does not want to install 15.2. My first attempt it downloaded the update and got to "Preparing..." but after several minutes produced an error message that stated "Could not finish preparing." My second attempt it downloaded the update again and got past "Preparing..." shutdown the laptop and then made it to the black screen showing progress. After several minutes (during which I was not watching) it asked me to login. This is common in the middle of updates. But once I logged in it appeared to be done. I then checked and it was still running 15.1.1. No error message. It just simply did not install 15.2. I then tried a third time and it was in the process of downloading (for the third time) the update. I thought better of this and canceled the update entirely. I've never had this experience with any update in the past.

My 2019 MP took the update, but devices (keyboard, mouse, external RAID) connected via Thunderbolt adapters are not recognized after initial Filevault unlock. USB-A keyboard connected via adapter works for the initial password entry at bootup but not at the login screen. Same keyboard/mouse works fine if directly connected to a USB-A rear panel port. This affects Apple TB2 to TB3 and Lightning to TB3 (iPhone) adapters and 3rd party USB-A to TB3 adapters connected to any of the Mac rear panel TB ports or XDR display TB ports. System Report says no Thunderbolt drivers loaded. Attempts to re-install via recovery unsuccessful so far. Install does not seem to complete.

I had this exact issue. I used screen sharing on a 2nd mac on the same network and i was able to connect to the mac with the problem and found a desktop that was up and running -- just not showing on the actual monitor. I was able to continue my troubleshooting from there (i.e. i shut down, booted into safe mode, etc, reset pram and have at least for now solved that problem. I am still having other thunderbolt issues with a blackmagic multidock that I am still working on.

Just want to follow up...I did some troubleshooting and found that when my OWC thunderbay (thunderbolt 3) plugged in and turned on at boot, the thunderbay drives DO NOT load. When I turn off the thunderbay and reboot then turn on the thunderbay all of the drives load normal. Might be a OS glitch?