Since Windows 10 update, Thunderbird now opens endless copies of attached pdf files
If I click on a pdf attachment, Thunderbird opens endless copies in new tabs. Only way of stopping it is to keep closing multiple tabs. After about 10 goes, it stops downloading. I have temporarily solved it by changing the default pdf app, but I would prefer to go back to how it used to work before the most recent, and very annoying Windows 10 update. Please advise.
Opaite Mbohovái (1)
Chances are Thunderbird is set to open PDF files for you, where in fact that should not be done - also see this support article for Firefox for a similar issue. That, or the file that stores the info is damaged.
Open your Thunderbird profile folder, close Thunderbird and remove, rename or move either the file called mimeTypes.rdf or handjers.json in that folder (or just both), depending on your Thunderbird version. After starting Thunderbird there should be no listing of PDF files in the Options > Attachments tab > Incoming tab afterwards and clicking such file type should prompt what to do.
If that doesn’t help, Windows itself may have set Thunderbird to open PDF files after the update for an odd reason (or you did so manually?), and I don’t think that should happen.