If you are having problems with Translucent Backgrounds like this topic
C:\Users\YOUR WINDOWS USERNAME\AppData\Roaming\Microsoft\Windows\Themes
Delete "TranscodedWallpaper" file.
Delete "Transcoded_000" file (or any file with similar name).
This should fix it.
This problem may occur with or without third party wallpaper changers. I only use Windows 10's built-in slideshow option, sometimes it happens.