Wallpaper on iMac not appearing
Since I upgraded to Sonoma my iMac has been misbehaving with the Wallpaper. It just appears as gray fields. Do you know how to fix this? The Sonoma upgrade has caused lots of little problems for my 2019 iMac.
You may need to reinstall the OS, but...
Start with this of M1 or M2 Mac...
On your Mac, choose Apple menu > Shut Down.
Wait for your Mac to shut down completely. A Mac is completely shut down when the screen is black and any lights (including in the Touch Bar) are off.
Press and hold the power button on your Mac until “Loading startup options” appears.
Select a volume.
Press and hold the Shift key, then click Continue in Safe Mode.
The computer restarts automatically. When the login window appears, you should see “Safe Boot” in the menu bar.
Restart normally.
Start with this if IntelMac...
Safe Boot, (holding Shift key down at startup), does the problem occur in Safe Mode? Could take 10 minutes or more.
Safe mode attempts to repair Disks & clears lots of caches & loads safe Drivers, & prevents loading of 3rd party extensions, so if Safe Mode works try again in regular boot.