I converted a DC, CAS/HUB, and Mailbox server to VMs in a virtual environment for testing upgrades. I cleaned up AD and the DAG so that everything seems to work fine except for one thing:
Only members of the Organization Management group can log into OWA. Everyone else gets "The user name or password you entered isn't correct. Try entering it again." I added a test user to every Exchange Security group except Organization Management,
and I could not log into OWA. I could only log in when I added it to Organization Management.
Outlook works fine for all users. OWA works fine for all members of Organization Management.
(I'm running Exchange 2010 SP3 CU1 on Server 2008 R2. I would have posted to the Exchange 2010 forum, but that option isn't available on this New Question form.)