Q: Mountain Lion desktop wallpaper won't change!

I've found the source of the problem, at least for me, but not the solution. It turns out that all pictures up to a certain one ( an accidental screenshot off a contacts page) will work on the desktop, and all after it will revert to default mountain. So I delete the screenshot from Photos, and empty the trash and restart, but that particular photo still appears in the album as viewed in Desktop and Screensaver Prefs. So now what?

You might want to consider starting a new discussion. Since this one is a couple of years old, less people are likely to look at it. A new post would be much more visible. You can link to this one.

Might be a corrupt .plist.

Do a backup, preferably 2 backups on 2 separate drives.

Go to Finder and select your user/home folder. With that Finder window as the front window, either select Finder/View/Show View options or go command - J.  When the View options opens, check ’Show Library Folder’. That should make your user library folder visible in your user/home folder.  Select Library. Then go to Preferences/com.apple.finder.plist and com.apple.desktop.plist.  Move the .plists to your desktop.

Re-launch Finder by restarting the computer and test. If it works okay, delete the plists from the desktop.

If the same, return the .plists to where you got it  from, overwriting the newer one.

Thanks to leonie for some information contained in this.

Eric

Thanks for this. I’ve done what you suggest, but there isn’t a desktop.plist. I might try creating one, although you’d expect it to create one if one had deleted it.

Best

Brian