Unable to change wallpaper on my Mac post Sonoma update

I solved it by simply move my wallpaper folder from iCloud to my Pictures (local) folder.

I solved it by putting the photos I want to use (about 150) in a folder on my Mac, not in the cloud files. Logged out and back in and voila!

This worked for me. It won't pull from iPhotos, make a folder, export pics to that folder and use that.

Same exact problem here. It seemed to be better after a Safe Boot (and then back to a normal boot), It was working shuffling through an album every 1 minute. I changed to 5 minutes and it reverted to default again. More testing needed, but it's clearly broken.

I verified with Apple that all of the wallpaper-related issues with Sonoma are different manifestations the problem I described earlier. I have been working with low-level OS code for decades and this type of thing is very common, albeit most of the time it's caught during unit/alpha/beta testing. Granted, the issue(s) could've been hashed out better, but hindsight is 20/20.

Once the root cause is found (if not already), the fix will most likely be simple and it will have the appearance of solving multiple problems -- this is because all wallpaper-related features use a common set of subsystem calls. If one of those system calls is buggy, LOTS of features will appear to be individual bugs.

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@Richard Amis: thank you, yours is the only reply that seems to work for me. The logout/login didn't work, so for now I've individually clicked about 20 images from my "backgrounds" album, then clicked the shuffle again. These 20 images are now shuffled.

And waiting for the next Sonoma release in the hope this is fixed.

Apple posted an update to Sonoma yesterday -- download and install for fixes

I had the same experience after following the Mission Control suggestion. After restarting my iMac, I had only the grey/black screen - except on the additional screens created through Mission Control. I spent nearly two hours on phone with Apple Care yesterday. The end result was a suggestion from a senior advisor that the problem is my user profile and I'll need to wipe my computer clean and rebuild from Time Machine. Not willing to do that yet.

KitzW wrote:

I solved it by putting the photos I want to use (about 150) in a folder on my Mac, not in the cloud files. Logged out and back in and voila!

That is not a solution, that is a work-around. A folder on your Mac with photos does work with the random feature in the Wallpaper settings panel. It still does not work if you want to randomize photos from an album in your Photos application. Doesn't matter if they are in the cloud or local on your Mac. It won't randomize or even display a photo if you choose the random option for an album in your Photos app. All you get is the Apple Vineyard wallpaper. Apple still needs to fix this.

I tried the _click on the ones you want to shuffle, then click on the shuffle icon on the item below the folder's name__, and it appears to be working. The folder was constructed in Photos and downloaded to the desktop. The download worked, BUT it didn't place the downloads into a folder. I need to see what I did wrong there. There are only 35 photos so it was not a problem. I then told the wallpaper system setting to choose that folder, did the "click the shufflers" routine. I set it to cycle every minute, and it is. I will update you if something goes awry.

I noticed when changing that it took a bit of time for the wallpaper (at least the Landscape ones) to download after I clicked on them.

If that didn't solve, try going to applications/utilities/disk repair -- run disk repair and the restart your computer when finished.

The same thing happened to me. I left it overnight and when I came back it was working as intended. My guess was that it needed to download a large number of videos... Which everyone else was also downloading at the same time.