I’m running a macOS Big Sur Beta installer from Recovery after erasing my drive, and after running a Reinstall macOS utility for over an hour, this Update Assistant appeared. The progress bar is not moving, wireless keyboard and trackpad disconnected, I can’t find any information on this utility on the web. I’m aware of various rebooting methods, instead, I’d like to find out if anyone is familiar with the said assistant and possible reasons for its appearance on my screen. See photo: https://discussions.apple.com/thread/251741106

Mac mini (late 2014) macOS 10.15.6 running from a bootable microSD card (inserted into SDXC slot) Enrolled my Mac into the Public Beta program, downloaded macOS Big Sur Beta through Software Update (I do assume it downloaded the latest version i.e. Beta 5?), ran an update. After a few hours updating, it stuck on “less than a minute remaining” for a good hour, then rebooted and hang up on the black screen with Apple logo. Diagnostics and Disk Utility’s First Aid find no issues. Rebooting in Safe Mode presents with a login window but gets stuck when progress bar reaches 100%. Clearing NVRAM and rebooting in Recovery mode leads to the same black Apple screen eventually. I then rebooted in Verbose Mode. Terminal displayed many ‘failed to bootstrap path’ error notices, but nevertheless continued running the boot until it hang and resolved to black Apple screen. Before switching to the black screen, it displayed the following: setSystemTargetUUID will use / as the target Found update container: LPAPFSContainer: AppleAPFSMedia Found update container but did not find update volume.  mountAndGetUpdateVolumeMountPoint defaultMountPoint failed to get defaultMountPoint process_update_result_state: no update result file, assuming 1st boot after a restore OSVersion changed. Notifying clients  Attempting to cleanup saved RecoveryOS state.  RecoveryOS status file not present(not an error) RecoveryOS connectivity data file not present  Clearing out RecoveryOS logarchives  Deleting RecoveryOS logarchive files Using default RecoveryOS logarchive preservation timeout I thought issues with APFS containers were resolved in beta 5 release? Resolved in macOS Big Sur 11 beta 5 APFS containers with non-default allocation block sizes are now supported for installation. (64312561) Terminal then proceeds scheduling kernel threads. The very last lines before it hangs and switched to the black screen: en2: promiscuous mode enable succeeded  _dill_attach_flowswitch_nexus: en2 9000 1500  en3: promiscuous mode enable succeeded  _dill_attach_flowswitch_nexus: en3 9000 1500 IOConsoleUsers: time(0) 0->0, lin0, llk1, IOConsoleUsers: gIOScreenLockState 3, hs 0, bs 0, now 0, sm 0x0 Got incomplete channel sequence length 0, should be 16 postMessage::1412 APPLE80211_M_BSSID_CHANGED received  en1::IO80211Interface::postMessage bssid changed  AirPort_BrcmNIC::getSSIDData(): Get failure: APPLE80211_IOC_SSID: 02 How can AirPort function be the one that breaks the boot? Do I read it correctly? Any thoughts on what might have gone wrong?