Make sure the fiirmware is the latest.
Make sure if using SMB that the port is 445, not 139 (139 is SMB1 with Netbios)
Make sure you are not setting it up with Right-click > Share With option as that is not SMB.
And lastly, unlike previos versions of Windows, you can't use anything but the username as it lists in the permissions (contained in brackets) So if it is user@domain, domain\user etc etc, it must be entered on the printer exactly as seen there.
Excuse the Win7 screenshot
