Your security certificate has expired
Using Chrome, Todoist is showing as being 'offline' (hence I cannot sync using https).
When I tried to open a new session, I was greeted with:
The site's security certificate has expired!
You attempted to reach todoist.com, but the server presented an expired certificate. No information is available to indicate whether that certificate has been compromised since its expiration. This means Google Chrome cannot guarantee that you are communicating with todoist.com and not an attacker. Your computer's clock is currently set to Wednesday, October 16, 2013 3:51:38 AM. Does that look right? If not, you should correct the error and refresh this page.
You should not proceed, especially if you have never seen this warning before for this site.
Proceeding anyway, my address bar shows https with a slash through it!
Definitely as above, happening to me too in Firefox (need to 'add exception' at the moment to open page);
This Connection is Untrusted
You have asked Firefox to connect securely to todoist.com, but we can't confirm that your connection is secure.
Normally, when you try to connect securely, sites will present trusted identification to prove that you are going to the right place. However, this site's identity can't be verified.
... and seems to be also affecting Outlook Plugin's ability to connect/update/sync perhaps as it's not up to much either.
Got this error as well today.
Will not use a web service that cannot keep its security certificate up to date :S
I got this too. I am also unable to authenticate from the android app, most likely due to this same error I would think.
Working now ... thanks!
We're very sorry for the inconvenience, this issue has been fixed now and our certificate renewed.