Hi, I have created a new property under Manage User Properties and mapped the property to an extension attribute, and then perform a full sync.

Under Manage User Profiles, I see the new field for the property I created, an I also am able to see the imported value from AD, if I add something here, and run a sync.

However if I go to Search Service Application-->Search Schema-->Add a mapping, I am unable to find the newly created property. Anyone experienced this, or know what I am doing wrong?? Full sync and crawl has been performed numerous times, with no luck whatsoever.

Make sure the Indexed option is checked in the Search Settings for the user profile property.