Using WSUS having issues with clients showing downloading 0% or not downloading windows 10 feature updates and thus the update failing, make sure you have this setting set in your WSUS server:
1) Open IIS Manager -> Select the server name from left penal -> Open “MIME Types” (Below Image for reference)
2) In MIME Type window: Actions -> Select “Add”
3) Add below details:
File name extension: .esd
MIME type: .esd application/octet-stream
Click OK
4) Restart IIS service from IIS Manager -> Select the server name from left penal -> Actions (Right side penal) -> click on Restart.
Once above steps are completed, Windows 10 clients should have this happen automatically in next update cycle.
