Apple Releases OS X Mountain Lion Developer Preview 3
Just over a month after the arrival of the previous build, Apple today seeded registered members of the Mac Developer Program with the third developer preview version of OS X Mountain Lion.
The new version arrives as Build 12A178q, up from the earlier 12A154q version. Changes included in the new version have yet to be discovered, but those with access to the build will undoubtedly be searching for Apple's latest tweaks as the company continues to work on the next-generation operating system.
Apple does list a number of known issues with the current build:
- 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
Apple also appears to be continuing to put a fair amount of effort into getting Game Center up and running on OS X with the new build.
OS X Mountain Lion is Apple's next major operating system version and is scheduled for release in "late summer". The release will offer greater integration with iCloud, as well as a number of new feature including some drawn from iOS.
Popular Stories
Despite being more than two years old, Apple's AirPods Pro 2 still dominate the premium wireless‑earbud space, thanks to a potent mix of top‑tier audio, class‑leading noise cancellation, and Apple's habit of delivering major new features through software updates. With AirPods Pro 3 widely expected to arrive in 2025, prospective buyers now face a familiar dilemma: snap up the proven...
If you have been experiencing issues with wireless CarPlay in your vehicle lately, it was likely due to a software bug that has now been fixed.
Apple released iOS 18.4.1 today, and the update's release notes say it "addresses a rare issue that prevents wireless CarPlay connection in certain vehicles."
If wireless CarPlay was acting up for you, updating your iPhone to iOS 18.4.1 should...
Apple's iPhone development roadmap runs several years into the future and the company is continually working with suppliers on several successive iPhone models simultaneously, which is why we often get rumored features months ahead of launch. The iPhone 17 series is no different, and we already have a good idea of what to expect from Apple's 2025 smartphone lineup.
If you skipped the iPhone...
Apple is preparing a "bold" new iPhone Pro model for the iPhone's 20th anniversary in 2027, according to Bloomberg's Mark Gurman. As part of what's being described as a "major shake-up," Apple is said to be developing a design that makes more extensive use of glass – and this could point directly to the display itself.
Here's the case for Apple releasing a truly all-screen iPhone with no...
While the iPhone 17 Pro and iPhone 17 Pro Max are not expected to launch until September, there are already plenty of rumors about the devices.
Subscribe to the MacRumors YouTube channel for more videos.
Below, we recap key changes rumored for the iPhone 17 Pro models as of April 2025:
Aluminum frame: iPhone 17 Pro models are rumored to have an aluminum frame, whereas the iPhone 15 Pro and ...
The first iOS 19 beta is less than two months away, and there are already a handful of new features that are expected with the update.
Apple should release the first iOS 19 beta to developers immediately following the WWDC 2025 keynote, which is scheduled for Monday, June 9. Following beta testing, the update should be released to the general public in September.
Below, we recap the key...
This week saw rumor updates on the iPhone 17 Pro and next-generation Vision Pro, while a minor iOS 18.4.1 update delivered not just security fixes but also a fix for some CarPlay issues.
We also looked ahead at what else is in Apple's pipeline for the rest of 2025 and even the 20th-anniversary iPhone coming in 2027, so read on below for all the details on these stories and more!
iPhone 17 ...
Apple TV+ is currently available at a much lower price than usual, but time is running out if you want to take advantage of the offer.
In the U.S., new and qualified returning customers can subscribe to Apple TV+ for just $2.99 per month, for three months. Afterwards, regular pricing of $9.99 per month applies. The offer is available in the Apple TV app, and at tv.apple.com, through April...
