"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