The recent new insider build of Windows 10 (build 14251) has some pretty intense updates. There are also some known issues, but this is not one of them.
After updating to build 14251, if WindowFX is installed and enabled on the system explorer.exe will not be able to run and the user will be duped to their desktop with nothing but a black screen and a cursor.
If you are savvy enough like I was; You can open an elevated command prompt, navigate to "C:\Program Files (x86)\Stardock\WindowFX", run 'WindowFXConfig.exe' and turn off WindowFX. Then you will be able to start explorer.exe and have your desktop reappear.
I'm not asking for immediate updates, but for product stability and longevity, I thought it would be helpful to post my findings.