Upgraded Outlook for Mac from 15.8 to 15.9 today. Opened the app after the update and it continued to prompt for my Exchange password.
Set up a new identity. Same issue.
Deleted all keys in Keychain Access. Same issue.
Deleted and reinstalled 15.9. Same issue.
Setup Exchange account via Mail. Works.
Deleted 15.9 and reinstalled 15.8. Works.
Somethings not right with the update. Any ideas?
Running Yosemite 10.10.3 (14D131)