If you use the M3 Ultra version of Mac Studio, you may need to postpone upgrading to macOS 26.0 Tahoe. Currently, multiple users have reported that errors occurred during the upgrade process and ultimately caused the upgrade to fail. Users have also submitted posts on Apple's official forum for feedback. The specific performance is that the upgrade process is very smooth, but an error will not be reported until the upgrade is almost completed, and then the Mac will restart the system and return to version 15.7.
The problem appears to be caused by a bug in Apple's Neural Engine driver, where the installer failed a hardware check while loading the new Tahoe kernel driver for Apple's Neural Engine.
At present, Apple has contacted some users to collect kernel crash logs to check the root cause of the problem. It may take time to analyze and release fixes. Users using M3 Ultra Mac Studio may need to wait for the release of a new version.
Interested users can click here to view the discussion thread: https://discussions.apple.com/thread/256136192