Workaround for me was moving the ~/Library/Mail folder out to the Desktop and letting Mail remake the folder. Be aware, I'm not sure how destructive this is to attachments, settings and mbox contents, but it has let me load Mail to poke around for now and all Mail is being shown and searched with the same layout I had used previously.
Maraklov
Users receive reputation points by contributing quality content to the forums.
Posts include post and replies published on the forums.
Post authors can mark replies as Accepted to indicate successful solutions.
Apple Developer Forums admins can mark replies as Apple Recommended to indicate an approved solution
From
Bluffton, SC, United States