To go along with this morning’s third iOS 7 beta, Apple has released OS X Mavericks Developer Preview 3. This new preview arrives two weeks following Preview 2. Like Preview 2, it seems likely that Preview 3 focuses on bug and performance fixes.

OS X Mavericks launches for the general public this fall with new Maps and iBooks apps, significant battery life, scrolling, and overall performance adjustments, and power-user features like revamped multiple-monitor support, Finder Tags, Finder Tabs, and a faster Safari browser.

As readers discover changes in the new Mavericks preview, we will note them below. If you find anything new, you can reach us at

The update comes in at 1.08 GB.

Release Notes / Known Issues:


– Network migration from earlier versions of OS X requires the Migration Update for Snow Leopard, Lion, or Mountain Lion available form the Mac Dev Center.
– Migration from Windows is not supported in Developer Preview 3.
– Reinstalling Developer Preview 3 from the Recovery Partition is not supported. Developer Preview 3 can be reinstalled using a Time Machine backup or Target Disk Mode.

iCloud and iCloud Keychain

– The Reset Keychain button in Account Details of the iCloud preferences pane is for testing purposes and will not be available in the final release.
– First time iCloud setup may fail. Disabled services may be manually enabled in the iCloud preferences pane.
– After upgrading to Developer Preview 3, iCloud Keychain will need to be re-enabled in the iCloud preferences pane.
– iCloud Keychain in OS X Mavericks Developer Seed 3 is not backward compatible with iOS 7 Seed 2 and OS X Mavericks Developer Seed 2.
– When enabling iCloud Keychain, a blank sheet may appear. Force Quit System Preferences and retry.

Third-Party Applications

– Installation within a virtual machine is not supported for VMWare Fusion.
– Adobe After Effects CS6 will not function correctly.


– Screen recordings taken with Developer Preview 3 are not compatible with earlier releases of OS X.
– The QuickTime Player progress bar may be nonfunctional when opening media that requires conversion prior to playback.
– Aperture may exit unexpectedly when exporting an image while in full screen.
– Moving a full-screen Aperture window to a secondary display may prevent the app window from being visible in subsequent attempts to use full screen.
– When saving from Photoshop, ‘Save As’ may not respect selected filetype.
– Maps may display some graphical corruption when resizing windows or switching from standard to satellite view.
– Fusion Drive volumes created with Developer Preview 3 are not compatible with OS X version 10.8.4 or earlier.
– The headphone port on the new 2013 MacBook Air will not operate unless headphones are present at boot.
– On some machines, frequently sleeping and waking may result in the machine restarting.
– Developer Preview 3 includes OpenSSH 6.2p2.