there is a bug which we are working on right now and will notify you as soon as it's fixed. We're very sorry for any inconvenience it has caused you.
Please note that it only affects Internet Explorer (the Outlook plugin uses Internet Explorer to connect to Todoist) and you can access your tasks through any other browser (Firefox, Chrome, Safari, Opera) as well as the mobile site http://todoist.com/m
we have fixed this issue and you should be able to access Todoist through Internet Explorer and the Outlook plugin.
We're very sorry for the inconvenience.