Apple has just seeded OS X 10.8 Developer Preview 3 to developers. This release of Mountain Lion build 12A178q comes with some some bug fixes and also has some known issues that Apple has made available as part of release notes.

OS X Mountain Lion 12A178q

If you are a registered developer, you can now download OS X Mountain Lion 12A178q DP3 (Developer Preview 3). To access the download links, go to Apple Developer Center and log in with your account.



Since Developer Preview / Beta releases are meant for developers only, you cannot download it if you are not a registered developer.

Known Issues
– On systems with FileVault enabled, canceling the restart to the Mountain Lion Developer Preview 3 Installer may leave your system unable to present a password dialog at boot time. You
can repair the problem by holding down command-R to boot to the Recovery OS and then using Disk Utility to unlock and Repair your volume.
– Installing OS X 10.8 over 10.7.2 or earlier with FileVault turned on may fail
– Pre-Lion FileVault user accounts are not supported in this Developer Preview
– Some Apple menu items such as Restart may not work when a sandboxed app is in the foreground
– iTunes no longer syncs Notes
– Mail’s photo browser cannot access the iPhoto library
– Back to My Mac doesn’t work for the first 5 minutes after rebooting
– DVD Player may not launch after inserting a DVD on some systems
– Most help topics are unavailable in this Developer Preview
– In the Recovery HD:
– Some icons may be missing
– Network Utility’s Lookup pane does not work
– Time Machine restoration via a AFP share does not work
– Restoring from a Time Machine backup via AFP does not work
– Migration from a Time Machine backup that excludes paths such as /System may yield an unusable system
– Brightness settings may change unexpectedly after reboot
– Display brightness may be dim after sleep or reboot
– If Mail is hidden at logout time, it may not be correctly relaunched during a subsequent login but will appear to be running
– Java applets may not work in Safari
– QuickTime screen recordings may produce corrupted videos or cause an exception when run on machines with NVDIA graphics
Game Center
– In this seed, the Game Center application will view Production data by default. Games in development will be programmatically switched to use the Sandbox server environment
– No Top Games are displayed on the Me tab and no game recommendations are shown on the Games tab
– To use Game Center in your game on OS X, you must install a provisioning profile that enables Game Center for your app. Code signing, entitlements, and provisioning profiles are all
described in detail in Tools Workflow Guide for Mac
– Multiplayer gaming with Game Center between iOS and OS X is not available in this seed
– In the Game Center app, game detail information such as game provider, pricing, etc. is not displayed
– The local peer-to-peer GameKit API (GKSession, GKPeerPickerController, and related classes) is not supported