Why can't I set a report as default on Browser User Interface?
Browser User Interface (BUI)
Oracle Service Cloud versions below August 2015
Unfortunately to get "Set as Browser Desktop default" feature on Browser User Interface (BUI), your Oracle Service Cloud smart client version must be at or above August 2015. Therefore, to get this functionality in the Browser UI you must upgrade your Oracle Service Cloud site to the most current version.
For information on upgrading, refer to Answer 1124: Requesting an Oracle Service Cloud Update.
Although Browser UI (BUI) can be thought of as single version, the Oracle Service Cloud smart client is not and may be missing functionality that is available in the version of BUI.
"Set as Browser Desktop default" is one functionality that is not available to BUI until Oracle Service Cloud version August 2015.