Hi Chris, I've just tried dragging a message to another folder in Firefox Beta on macOS, and it works here. If you start Firefox in Troubleshoot Mode, does the problem still occur? To start in Troubleshoot Mode, go to Help > Troubleshoot Mode.

If the problem does not occur in Troubleshoot Mode, then you can disable your extensions one-by-one until you find out which one is causing the problem. For more info, visit Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems.

Thank you. I started the browser in Troubleshoot Mode and it is still occurring. Any further suggestions would be appreciated.

Is this question about dragging messages between folders or dragging files on a new mail window?

Dragging files into a new mail window. Thanks.

This is a known issue with dragging a file in OWA and is possibly something MS needs to be done on their side. A possible workaround for now is to attach the files instead of dragging. See comment 18 (1763027#c18).

I've just heard back from Microsoft, and they are actively working on a fix that might be ready next week. I'll update this bug as soon as we know more!

• 1763027 - outlook.office.com - drag and drop attachments not working

(please do not comment in bug reports
https://bugzilla.mozilla.org/page.cgi?id=etiquette.html)

Thank you. I have been using the attach button instead, but as someone who spends much of his work day attaching items, that can be quite time consuming. I look forward to the update and hope it corrects the problem.

Hi Chris, A fix for this issue has been released. To update to the latest version, go to Firefox > About Firefox. There are more detailed instructions in the following article: Update Firefox to the latest release

If you still have the issue, please let us know.