backup zip ,841mb ,will not import into thunderbird

''<p> [[#question-1595090|said]]</p>'' <blockquote>Used the export function to export to zip file on a usb, (841mb) can see the zip file is there, then open thunderbird on desktop (Zorin 18.1) choose import , choose the zip file and get a message "nothing can be imported from the selected source" bit frustrating, hope one of you gurus can sort me out. Cheers John </blockquote> The desktop thunderbird already has accounts and folders installed, and the export zip I want to use is from a ext SSD I used to try Zorin before I installed to a m.2 drive on the MoBo I did a lot of work on the SSd Thunderbird not realising it wouldnt migrate to my M.2 install. Hope that helps