Exchange 2010 SP3 RpcProxy not working.

After doing an Upgrade of Exchange 2010 SP2 to SP3 the RpcProxy/ Outlook Anywhere stopped working.

Eventlog on Exchange server showed lots of:

Event ID 1310

Application information:

Application domain: /LM/W3SVC/1/ROOT/Rpc-18-130144692505559065

Trust level: Full

Application Virtual Path: /Rpc

Application Path: C:\Windows\System32\RpcProxy\

Machine name: MS-NO-SVG-01


Process information:

Process ID: 7156

Process name: w3wp.exe

Account name: IIS APPPOOL\DefaultAppPool


Exception information:

Exception type: ConfigurationErrorsException

Exception message: Could not load file or assembly ‘Microsoft.Exchange.RpcClientAccess.Coexistence, Version=, Culture=neutral, PublicKeyToken=31bf3856ad364e35’ or one of its dependencies. The system cannot find the file specified.


After some research I found out that the RPCProxy webconfig file was strange/corrupted .

All Path’s in the file was incorrect: (snipp from c:\windows\system32\rpcproxy\web.config)

 <codeBase version=”″ href=”file:///%ExchangeInstallDir%bin\Microsoft.Exchange.RpcClientAccess.Coexistence.dll” />


The correct should be:

<codeBase version=”″ href=”file:///C:\Program Files\Microsoft\Exchange Server\V14\bin\Microsoft.Exchange.RpcClientAccess.Coexistence.dll” />

Attached a file from a working server:

web-config.txt (67.89 kb)

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