We recently hit a milestone. A milestone I’ve hit many times before, but due to many factors this was a huge milestone. I’ve migrated my mailbox to Office 365 (Exchange Online), and last night everything just seemed to work. Of course there was the usual quirkiness. I had to force Outlook to connect, restart Skype for Business to re-sync the calendar. A curious thing happened the morning after as it sometimes does. When I launched Outlook, it asked me to login once, ok maybe I forgot to remember my password the first time. Outlook connected, but then Outlook kept asking me to enter my credentials even though it was connected.
After entering my password a few times, and restarting Outlook I had to sit back and think.
Could it be a firewall issue? not likely since the password prompt is making it through.
Why is Outlook connected? Could it be ADFS?
Then I took a look through the Windows Credential Manager and noticed that there was artifact that was left over.
I was further confused by why they were modified today, and if they were why was it still prompting me? As I went on it became clearer, I opened up a credential manager profile and nothing looked out of place, so I deleted them thinking Outlook would recreate them.
Once deleted from the Credential Manager, I started Outlook again and asked it to remember my credentials. This time there wasn’t an entry in the credential manager and everything worked as expected. Because Office 365 is a web service, it uses the Office 365 Sign-in Assistant (make sure you install that) https://www.microsoft.com/en-ca/download/details.aspx?id=39267