Macintosh HD - Data will not mount
macOS recently tried to update and failed. There is plenty of free space. When I boot to an external drive running Catalina, I can see the drive and partitions, except the DATA partition in APFS is not mounted, and will not mount with the known good password.
I've actually come across two users with this exact same issue and it appears to have something to do with the latest Big Sur update. Any ideas on how to get the data to mount to rescue it so we can wipe and go again?