Symptoms
Assume that you are using an Exchange Web Service (EWS) based application in a Microsoft Exchange Server 2010 environment. In this situation, you cannot access mailboxes, and you receive a "503 Service Unavailable" error. Additionally, the following events are logged in the Application log on the Exchange Server 2010 Client Access server:
Log Name: Application
Source: MSExchange Common
Date: Date
Event ID: 4999
Task Category: General
Level: Error
Keywords: Classic
User: N/A
Computer: Computer
Description:
Watson report about to be sent for process id: Process ID, with parameters: E12, Build Type, Version Number, WS, System.Web, S.W.U.WebServiceParser.GetCompiledType, System.InvalidCastException, XXXX, Version Number.
ErrorReportingEnabled: True
Log Name: Application
Source: ASP.NET 2.0.50727.0
Date: Date
Event ID: 1309
Task Category: Web Event
Level: Warning
Keywords: Classic
User: N/A
Computer: Computer
Description:
Event code: 3005
Event message: An unhandled exception has occurred.
Event time: Time
Event time (UTC): Time
Event ID: ID
Event sequence: XXX
Event occurrence: XX
Event detail code: 0
Application information:
Application domain: /LM/W3SVC/1/ROOT/EWS-1-XXXXX
Trust level: Full
Application Virtual Path: /EWS
Application Path: Drive:\Program Files\Microsoft\Exchange Server\ClientAccess\exchweb\EWS\
Machine name: Computer
Process information:
Process ID: Process ID
Process name: w3wp.exe
Account name: NT AUTHORITY\SYSTEM
Exception information:
Exception type: InvalidCastException
Exception message: Unable to cast object of type 'System.Web.Compilation.BuildResultCustomString' to type 'System.Web.Compilation.BuildResultCompiledType'.
Request information:
Request URL: URL
Request path: /EWS/Exchange.asmx
User host address: IP
User: User
Is authenticated: True
Authentication Type: NTLM
Thread account name: NT AUTHORITY\SYSTEM
Thread information:
Thread ID: Thread ID
Thread account name: NT AUTHORITY\SYSTEM
Is impersonating: False
Stack trace: at System.Web.UI.WebServiceParser.GetCompiledType(String inputFile, HttpContext context)
at System.Web.Services.Protocols.WebServiceHandlerFactory.GetHandler(HttpContext context, String verb, String url, String filePath)
at System.Web.HttpApplication.MaterializeHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)
Cause
This issue occurs because the Exchange server does not use a correct handler to process the EWS request.
Resolution
To resolve this issue, install the following update rollup:
2785908 Description of Update Rollup 5 version 2 for Exchange Server 2010 Service Pack 2
Status
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
