The OS X Yosemite 10.10.5 update improves the stability, compatibility, and security of your Mac.
• Improves compatibility with certain email servers when using Mail
• Fixes an issue in Photos that prevented importing videos from GoPro cameras
• Fixes an issue in QuickTime Player that prevented playback of Windows Media files
You can update to OS X Yosemite 10.10.5 from the Mac App Store through the Updates tab.
Apple also released iOS 8.4.1 today with improvements to Apple Music.