After switching to Lubuntu, then installing Thunderbird and pasting my old profile, Tbird starts and all account settings are correct, even the old email arrive correctly. However, the folders for sorting all the email are missing. When the folders for sorting are recreated and all the email sorted, if Thunderbird is closed, none of the folders return on restart, though all of the emails do return, even new email that gets deleted. So the emails keep growing in number every time Tbird starts. Everything related to profiles from the new install has been deleted, and the old profile pasted in the root and local directories. Clearly something is being missed, and no one else seems to be having this problem specifically. So, everything works except folders and deleting email on restart. The version of Tbird which created the pasted profile is unknown.