I was trying to change my wallpaper but I keep getting the message "can not set wallpaper from sandboxed process."
What I did was click the Picotron menu at the top left > System Settings > and then the wallpaper section under the desktop tab. This is without any custom wallpapers, trying to switch between the default ones.

Whenever I click a wallpaper it shows the error message. It only gets applied after a reboot.

Adding:
It happens on both my Windows 10 Desktop and Windows 11 Laptop.