to_vaib: My apologies - I do see that you said that. We did our CU23 updates back in November so I don't remember it very clearly. However, I did find the steps we went by:
Install procedure
- Extract the exchange media and run the following Prerequisites:
- Run setup.exe /PrepareSchema /IAcceptExchangeServerLicenseTerms (requires Enterprise Admins and Schema Admins permissions, and must be performed in the same AD Site as the Schema Master on a server with the RSAT-ADDS-Tools feature installed – the Schema Master itself would meet these requirements)
- Run setup.exe /PrepareAD /IAcceptExchangeServerLicenseTerms
- Run setup.exe /PrepareDomain /IAcceptExchangeServerLicenseTerms in each domain in your forest that contains Exchange servers or mailboxes
- Install the following:
- .net 4.7.2
- https://dotnet.microsoft.com/download/dotnet-framework/net472
- Visual C++ Redistributable Packages for Visual Studio 2013
- https://www.microsoft.com/download/details.aspx?id=40784
- Microsoft Exchange Server 2013 Cumulative Update 23:
- https://www.microsoft.com/en-us/download/details.aspx?id=58392