I have a problem with Exchange 2007 OWA. The browser gives me back this error message:
Initialization of Outlook Web Access failed.
Invalid theme info file in folder 'base'. Line 0 Position 0. XML parser error. Root element is missing.
I've read several articles about repairing this thing. You must copy the theme files from the Exchange 2007 dvd Setup\ServerRoles\ClientAccess\owa\version\themes back to the server to owerwrite corrupt files and do an iisreset.
I've done that but it doesn't work! I got the same error message.