Hot Corners can be configured to disable the screen saver by moving the mouse cursor to a corner of the screen. Rationale: Setting a hot corner to disable the screen saver poses a potential security risk since an unauthorized person could use this to bypass the login screen and gain access to the system.
Solution
Perform the following to disable a Hot Corner set to Disable Screen Saver: Graphical Method: Open System Preferences Select Desktop & Screen Saver Select Screen Saver Select Hot Corners... and turn off any corner that is set to Disable Screen Saver Terminal Method: Run the following command to turn off Disable Screen Saver for a Hot Corner: $ sudo -u <username> /usr/bin/defaults write com.apple.dock <corner that is set to '6'> -int 0 example: $ sudo -u seconduser /usr/bin/defaults write com.apple.dock wvous-tl-corner -int 0 $ sudo -u seconduser /usr/bin/defaults read com.apple.dock wvous-tl-corner 0 Profile Method: Create or edit a configuration profile with the PayLoadType of com.apple.dock Add the key Forced Set the key to the following: <array> <dict> <key>mcx_preference_settings</key> <dict> <key>wvous-bl-corner</key> <integer><!=6></integer> <key>wvous-br-corner</key> <integer><!=6></integer> <key>wvous-tl-corner</key> <integer><!=6></integer> <key>wvous-tr-corner</key> <integer><!=6></integer> </dict> </dict> </array>