Some users are unable to open free busy information in Outlook 2013 and also unable to set OOF when using Outlook 2013. It  is getting the following prompt when trying to access their automatic reply settings:
"Your automatic reply settings cannot be displayed because the server is currently unavailable".

It works when i run outlook.exe/cleanroamedprefs

Can you make any change in Exchange 2013 to make it work witout any outlook switch

Hi,

According to your posting, I noticed the issue can be resolved by the Outlook Switch.

Please confirm whether the issue happens to all Exchange users. Also check if the problematic users can use OOF or free/busy information in OWA. If the issue only happens to some issue instead of all users, please create new Outlook profile for the problematic users or upgrade Outlook 2013 to the latest version to have a try.

If the issue happens to all users, please access your EWS url (OOF url) from IE to check whether a proper XML page can be returned.

Regards,