To catch you up quickly, Microsoft delivered an update in June 2016 that essentially broke Group Policy for many organizations. Read through these:
An OS rollup is causing Hyper-V problems.
A fix for the Windows Update client is available that attempts to solve long update scans.
There's now a resolution available for those affected by Patch Tuesday's KB3163622.
A security update for Group Policy for this month doesn't quite work as expected.