When I click the TD Add button, it opens a blank Todoist window at the bottom right. Can't add my task from an email. Works on windows at work.
Which browser are you using? Do you have Third Party Cookies Enabeled, and Preview Pane (Gmail Labs) disabled?
Chrome. Preview pane is off. Allow local cookies is checked. Block 3d party cookies is not checked.
Just started working. I didn't change any settings. Not sure why it works now.