I have received this installation error attempting to upgrade from MacOS 26.4 beta 2 to beta 3 on my Intel 2020 27” iMac, and now trying to install beta 4 from beta 3 on my M1 Max MBP. I have seen from a sprinkling of post that some others have had the same issue. I was able to successfully perform the 2 to 3 upgrade on the iMac in safe boot, suggesting possible compatible, third-party app. But that did not work for beta 4 on either device. I have submitted feedback for each episode. Any others have this issue? Unusual for Apple, I have never had any issues installing beta software before.

After crash and unexpected reboot of Oracle VirtualBox app on MacOS Monterey beta, Disk Utility on Macintosh HD shows a huge list of "warning - orphan omap mappings found for old xxxxxxx" or "for old range xxxxx-xxxxx". Disk Utility says "performing deferred repairs" and "exit code 0. volume appears to be OK", but errors persist on rescan. Does this need to be fixed, and how? Thanks. (reported on Feedback Assistant also).