Post CU23 update excahnge issues

Question

Server2012R2 Std
Exchange 2013 CU23
Patch applied

IN/out is working on mailboxes to outlook 2012/2019.
I tried OWA web access and got the login in then "bad request"
I went to exchanger sever and tried to launch "Exchange Administrative Center" and got this...

Could not load file or assembly 'Microsoft.Exchange.Common, Version=15.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' or one of its dependencies. The system cannot find the file specified.

What happened and how do I correct it

Answer 1

Did you run the patch elevated?
https://learn.microsoft.com/en-us/exchange/troubleshoot/client-connectivity/exchange-security-update-issues

If not, walk through the solutions in that link

Answer 2

@John Lenz

Here are detailed information from above article, try to reinstall this KB with administrator rights:

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Answer 3

My post did not take. Yes elevated now works