Outlook cannot connect to Exchange: event 15021

Good morning,

everything was fine this morning.  Exchange 2013 on Server 2012 R2, 30 Updates scheduled for install.  I installed them, rebooted.
Hundreds of events "15021 Http event" in eventlog.  
"An error occurred while using SSL configuration for endpoint The error status code is contained within the returned data."

I tried this:
No change.
I also tried this:

On the final command I get
The SSL-certificate could not be added.  Error:  1312
The specified login session no longer exists.  Maybe it was already closed.
(I am translating this from a German language installation).

That means that I deleted the entry and cannot re-add it.  Another reboot produces no more http-events in eventlog, but the users still cannot connect.

Help?  Anyone?

Ralph ScharpingDigital TherapistAsked:
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Does this help: https://technet.microsoft.com/en-us/library/cc727844(v=ws.10).aspx

Note, is your certificate still valid?
Ralph ScharpingDigital TherapistAuthor Commented:
Yes, Certificate is valid.
No chance with netsh.  
I opened IIS Manager and reconfigured the binding on port 444 not for the standard website, but for the exchange site.  That fixed it.

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Glad to hear it's resolved!
Ralph ScharpingDigital TherapistAuthor Commented:
Found it after looking further...
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