I do not know. What does Outlook.com have to say in their help. Has this anything to do with Firefox ??

''hermie2 [[#question-1179761|said]]'' <blockquote> I closed another email account and wish to copy and paste my contact list to Outlook.com </blockquote> Hi ! Assuming you want to export your contacts from Thunderbird : you really should post your question here : https://support.mozilla.org/en-US/products/thunderbird But, since you're here, maybe this will help : http://www.thunderbirdtooutlook.com/instruction/export-contacts-to-outlook/