attaching files to outgoing emails stopped working, what is going on?

Might be bug https://bugzilla.mozilla.org/show_bug.cgi?id=2077526 Did you already try to attach files via drag & drop?

I am having the same problem - started Tuesday Oct 6th around noonish.

(NOTE: Thunderbird had an automatic update Friday Oct 2 and there was also a fairly recent Windows 11 update to my computer in the last week or so as well.)

I didn't use the computer over the weekend. On Monday everything worked fine, as it did on Tuesday morning sending out pdf attachments (6-12 per day) to various clients.

Just after lunch Tuesday something went haywire with the "ATTACH" button in the top right corner and it stopped functioning. I did not make any changes to any settings in Thunderbird.

Everything else in Thunderbird seems to be functioning properly - I can send emails sans attachments and receive emails with attachments.

Thanks to Mapenzi for the tip above on DRAG & DROP - that at least allows me to stop using an old MSMAIL/OUTLOOK on a back up computer that I have linked to my DropBox.

I am not a tech guy but if anyone can fix this issue please help (using Drag & Drop slows things down considerably)