Installing Exchange 2016 CU4: Service 'WMSVC' Failed to Reach Status 'Running' On This Server

Upgrading our Microsoft Exchange 2016 servers to CU4 failed with this error:

"Microsoft.Exchange.Configuration.Tasks.ServiceDidNotReachStatusException: 

Service 'WMSVC' failed to reach status 'Running' on this Server"

The solution hint came from Paul Cunningham's Practical 365 Blog post: Service 'WMSVC' Failed to Reach Status 'Running' On This Server.

In our case, we had a valid SSL certificate.  Why did it mysteriously disappear from IIS' Management Service??? I reapplied the certificate, restarted IIS, and resumed the Exchange CU4 in-place upgrade.

Here is the error screen, btw:

Russ