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Fix 10.6.2's Broken Slide Show Screen Saver

After I upgraded to Mac OS X 10.6.2, I had to step out for an appointment. When I returned to my Mac, its screens were black, other than the dreaded spinning pizza of death. I realized the screen saver had crashed, but had to shut the Mac down forcibly since no other method I tried would give me control back.

I quickly isolated the problem to the Slide Show screen saver that's bundled with Mac OS X (see "Mac OS X 10.6.2 Addresses Myriad Bugs and Security Issues," 9 November 2009). It's used to display a slide show of pictures, either from a folder or from iPhoto. In the past, it has handled very large numbers of images with aplomb, which is necessary, since many thousands of images are necessary to prevent image-based screen savers from becoming boring.

After upgrading to 10.6.2, however, the Slide Show screen saver (tested via the preview in the Desktop & Screen Saver preference pane) took minutes to scan folders that it previously could scan in seconds. And with too many photos, the Slide Show screen saver would just hang, requiring a force quit of System Preferences. Folders containing a relatively small number of images worked fine. With no free time to investigate further, I just made sure the Slide Show screen saver wouldn't be used.

Kudos to Ernst Mulder, who also experienced this and figured out a workaround that he posted on Apple's Support Discussions forum (and thanks to TidBITS reader Judson Dunn for the pointer!). Ernst believes that the new version of Slide Show does a file-by-file scan of the available images (presumably for randomizing) instead of using a Spotlight search. As such, rebuilding the Spotlight index, reinstalling 10.6.2 using the Combo updater, and testing from a clean user account made no difference.

Then Ernst figured out that he could work around the problem by replacing a key component of the Slide Show screen saver package with one from 10.6.1. I've replicated his suggestion, and it does appear to work, though of course you need access to a Mac running 10.6.1 to be able to perform the fix. The file you need to replace is deeply nested, and you'll need to authenticate in order to copy it into the new location. It is:

/System/Library/Frameworks/ScreenSaver.framework/Versions/A/Resources/Pictures Folder.saver/Contents/MacOS/Pictures Folder

Note that to look inside "Pictures Folder.saver" you must Control-click the file and choose Show Package Contents from the contextual menu that appears; then you can navigate the rest of the way down to the necessary "Pictures Folder" file. It's probably worth making a backup of that file in 10.6.2 before replacing it with the file from 10.6.1, just in case.


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Comments about Fix 10.6.2's Broken Slide Show Screen Saver
(Comments are closed.)

Ernst Mulder  2009-11-11 09:58
Wow, after 22 years using the Mac I finally made it into TidBITS. :-)
Adam Engst  An apple icon for a TidBITS Staffer 2009-11-11 10:16
And good work it was too! We love it when readers contribute information that everyone will appreciate.
Daevad Tajkowski  2009-11-16 17:21
I have 10.6.2 slideshow screensaver pointing to a folder with 1764 images (number grows all the time) and it never has any problem showing a randomized display - on either a single monitor or with two monitors (different images show on each monitor), Clearly, this is not a universal problem. Or is 1764 not considered "large?"
I wouldn't consider that large. My iPhoto Library is about 9,000 images now, and I'd consider that to be at least approaching large. However, back on topic, it seems this crops up at some number between 1,000 and 3,000 photos. Might deepened on their size too?

I think your hint in the original article is "many thousands."

I've not had problems, but I point my slideshow to my 'best' album which only contains 800 or so photos.
Adam Engst  An apple icon for a TidBITS Staffer 2009-11-17 05:33
Alas, no, 1700 is not large. In my rough testing, I think the problem started to be noticeable in the 5000 range, and was truly problematic at the 8000 range. Beyond that, the screen saver simply didn't work.