Wallpaper Engine?

I can't seem to get Wallpaper engine to work correctly with BBLean, can anybody help me?

Sorry for the long delay, I haven't stopped by in a little while...

I take it that 'Wallpaper Engine' is a 3rd party wallpaper switching application, if so, you will have to change a Blackbox setting. Instead of giving you a short/sweet answer, Instead I'll quote the relevent section of the bbLean 1.17 help file:
 

Backgrounds

Generally, the background can be an image or a dynamically generated gradient. The background is specified in the current style with a line that starts like:

rootCommand: bsetroot -full "backgrounds\your_image.jpg"

Click on bsetroot.exe to get some help with it. See also the documentation for bsetroot.exe.

bbLean uses bsetroot.exe to generate the background and then either displays it on its own or lets Windows set the wallpaper, depending on the setting of 'Smart Wallpaper' in 'Configuration->Graphics'.

Also any processing of the rootCommand may be disabled in 'Configuration->Graphics'.

 

So, if you go to 'Blackbox->Configuration->Graphics' in the Main Desktop Menu (right-click) and untick 'Enable Background' then root commands in the style will be ignored, Windows is given back control of the desktop background and your app should function properly.

Pretty sure that will do it for you.