The OS X Mountain Lion v10.8.5 Update is recommended for all OS X Mountain Lion users. It improves the stability, compatibility, and security of your Mac.

Fixes an issue that may prevent Mail from displaying messages
Improves AFP file transfer performance over 802.11ac Wi-Fi
Resolves an issue that may prevent a screen saver from starting automatically
Improves Xsan reliability
Improves reliability when transferring large files over Ethernet
Improves performance when authenticating to an Open Directory server
Addresses an issue that prevented a smart card from unlocking preference panes in System Preferences
Contains the improvements included in MacBook Air (Mid 2013) Software Update 1.0

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