After hammering at the WSUS server (as it seemed to be server side from all the errors I found)...
Turns out to be something on the client side.
Give this batch - (how quaint) - a shot:
win10-wu-reset.bat
It might be good to disable some crapware as well:
Good article on clean boot here from Logitech:
http://support.logitech.com/en_us/article/228
To check the Windows Update logs on later versions of Windows:
1 - run Powershell. 2 - Get-WindowsUpdateLog 3 - profit! (not really)
Here is something to try to force updates to happen:
c:\windows\system32\usoclient StartScan c:\windows\system32\usoclient StartDownload c:\windows\system32\usoclient StartInstall c:\windows\system32\usoclient RestartDevice