I installed the plugin and nothing happens. I have Outlook 2010, I go to options add-ins and I do not see it in the list. I see it in the control panel as installed.
Please try to uninstall it through the Control Panel, have Outlook closed during this, then reinstall it "As Administrator" and see if it helps.
If not, please check if you see any logs in this location: %userprofile%\AppData\Local\Todoist\Outlook\ and if you do, email them to firstname.lastname@example.org and email@example.com incl. a link to this thread for reference.
It works now. Perfect.