I recently ran into an issue after updating to windows 10 1809, if I try using video wallpaper in displayfusion I get a black screen on my 4k display, I have discovered a workaround however it's not ideal. the only way I can get video wallpaper to work is to either change the resolution of my screen or right click the desktop and select Displayfusion - pause desktop wallpaper animations and then unpause it, then the video wallpaper shows up again but after a reboot it goes back to a black screen again, I also experienced something similar with stardocks deskapes, seems like it's something to do with the way windows 1809 handles the desktop. Anyway hopefully we can get a fix.

Yeah the wildlife video works but it's not a 4k video it's 720p, whenever I try a 4k video it blackscreens until I click pause desktop animations in the displayfusion menu then it starts playing again,. I'm running 2x displays in 1080p as well not sure if the different resolutions could be causing problems with the 4k display but yeah the wildlife video works but 4k videos still blackscreen until pause - unpause procedure.

Displayfusion was working ok with 4k content for a while in windows 10 1809 until I had to change the primary display from my 1080p to my 4k screen in windows to play a game then when I switched the primary monitor back to my 1080p display the video on the 4k went black and wouldn't load up regardless if I restarted or changed to another 4k video, the only solutions I could find was changing the resolution on the 4k screen or pause - unpause animation setting.