Windows 10 Start Menu not responding

Whilst at a client's office rolling out new infrastructure, I noticed that logging into all W10 machines caused some issues with the Start Menu.  Clicking on the Start Menu simply wouldn't do anything.  You could right-click on it without issue, but normal click did nothing.

This started to happen to all computers for all accounts.  I'd confirmed that everything was working well previously, so I started to look into whether it could be a new GPO rolled out or something like that.  Not being able to pin point any GPO which could have caused the issue, I started to investigate why the Start Menu wasn't  working.  Checking Event Logs, it showed that items were trying to register with the Firewall, but failing.

I checked the Services and the Windows Firewall service had actually been disabled.  After enabling this again, and starting it up, everything started to work.  It turns out a technician had gone through each computer and disabled the Windows Firewall service for some reason!

So if anyone has this issue with the W10 start menu, the first thing to check should be the Windows Firewall service!