I've got an issue with Windows Server 2012 R2, AD FS 3.0 providing SSO for Office 365 when a user tries to access their OWA.
When running ADFS with Forms Authentication the user is presented with the AD FS login page and is able to authenticate with their UPN. This is logged in the security log on the AD FS Server as would be expected when auditing is enabled.
However...
When running ADFS with Windows Authentication the user is presented with a login prompt (think Kerberos / NTLM dialog box) in IE and the user is unable to login with their UPN or Domain\Username. The login box keeps reappears 3 times then drops to a blank web page. There is also nothing logged on the AD FS Server to show any attempt to authenticate has been made.
Any suggestions would be gratefully received.
Thanks, Dan
