We have installed EX13 CU5 in a EX07 SP3CU12 environment.
I changed OWA Virtual Directory on EX13 to FBA with UserName option and selected the domain "fat.local"
Now when i run get-owavirtualdirectory on the EX13 machine no errors are reported and LogonFormat shows userName and DefaultDomain shows fat.local
But when i run get-owavirtualdirectory on the EX07 machine i get error referring to the EX13 OWA default web site saying;
"WARNING: Object DC-PEXCVS1\Exadmin (Default Web Site) has been corrupted and it
is in an inconsistent state. The following validation errors have occurred:
WARNING: You must set a DefaultDomain if LogonFormat is set to UserName.
Rather strange error cause it does not show this error when running on the 2013 machine.