Import from outlook is broken on Thunderbird 38. You will need to use Thunderbird 31 or earlier to do your import.

So how do we get Thunderbird 31 when we have 38?

ceserkland said

So how do we get Thunderbird 31 when we have 38?

You install it from the FTP site. http://ftp.mozilla.org/pub/mozilla.org/thunderbird/releases/31.6.0/

Pick your operating system and then your language to select the right installer for you.

That solves one problem, but I still cannot convince Thunderbird to import from my Outlook 2007

ceserkland said

That solves one problem, but I still cannot convince Thunderbird to import from my Outlook 2007

Are you trying to import from outlook which is installed on your computer, or from a PST or OST file, which is a file and not outlook.

I have M/S Office Professional 2007 installed on my computer; Outlook is part of that. It has been increasingly misbehaving, and I do now want to get into having to pay for Office on a subscription basis, so I want to shift to Thunderbird, but I want to keep my address book, emails (large batch) etc. I can live with out importing rules; those can be reestablished fresh when I get Thunderbird working for me. I can create a PST file if that can help further the process. T'bird said I needed Outlook to be the default mail client. I went into outlook and set it as the default client, but that did not help.

when you say outlook has been misbehaving, do you think it is possible it's mail store is damaged, hence it does not read it's data correctly and no import for that reason.

Try following these instructions to repair your office installation http://www.howtogeek.com/howto/microsoft-office/detect-and-repair-applications-in-microsoft-office-2007/