Here's what Software Update has to say about this update: This update is recommended for owners of MacBook, MacBook Air, and MacBook Pro with Mini DisplayPort. The update addresses an issue where some standard definition purchases from the iTunes Store do not play on some external displays.
We're sure that this update will make many MacBook and MacBook Pro users happy when it comes to video playback on external displays. You can download this update by opening Software Update (Apple menu > Software Update), or by visiting the Apple Support Download Website. Continue reading to see a screenshot of Software Update.
Update: Please note that this update does not allow the playback of HD (High-Definition) content on external displays, you will only be able to view SD (Standard-Definition) content.
Thanks to everyone who sent this in!
Apple MacBook Pro 13-inch (early 2015)