It blocks downloading Gmail attachments. Clicking on pdf or jpg to download do nothing. Uninstalling helps.

Like it says, doesn't work everywhere :/

Nicely done with a simple interface and well-documented, but doesn't seem to work everywhere. For example the .torrent files on http://hdreactor.info/ are still delivered as attachments with this extension active. Samlh, maybe you want to have look at this issue? I'd file a bug report but you don't seem to have a github or similar site.

I'm running Firefox 57 on Ubuntu 17.10.

EDIT: I've now replaced this extension with Header Editor (https://cup.aihedy.com/en-US/firefox/addon/header-editor/), a more generalized extension where I could quite easily define a rule to ignore those those pesky Content-Disposition: attachment headers on any website, including the one mentioned above.