If you’re having problems with themes on the Windows 10 Fall Creators Update, you can try the following:
Uninstall the theme:
- Open Settings.
- Click on Apps.
- Click on Apps & features.
- Select the theme you want.
- Click the Uninstall button.
If that doesn’t work, delete the themes you have installed from this location (You can use the Run command for quicker navigation):
Go to the personalization settings, and in the Themes section, click the link to open the Microsoft Store and try to download a new theme, but try to download a featured (a newer) theme.
Then on the Background settings, make sure the option is set to “Slideshow”.
If you’re still having problems, try to copy the DesktopBackground folder for the theme you want to use located inside the theme folder in
%LOCALAPPDATA%\Microsoft\Windows\Themes, and copy to the desktop.
Then go to the Background settings page, and using the Slideshow option, click the Browse button to select the DesktopBackground folder with the images you want to display.