You have a Microsoft Exchange Server 2010 server that has a public folder store installed in an Exchange organization.
You connect to the public folder store by using Outlook 2003.
You create a meeting request, and then you try to view the free/busy information.
In this scenario, the Microsoft Exchange RPC Client Access service on the Exchange server crashes. Therefore, users are disconnected from the server. Additionally, the following event is logged in the Application log:
Source: MSExchange Common Date: <date & time> Event ID: 4999 Task Category: General Level: Error Keywords: Classic User: N/A Computer: <computer name> Description: Watson report about to be sent for process id: <ID>, with parameters: E12, <build type>, <application version>, M.E.RpcClientAccess.Service, M.E.RpcClientAccess.Handler, M.E.R.H.CustomAvailabilityQuery.Query, System.NullReferenceException, <call stack hash>, < assembly version>.
This issue occurs because the Microsoft Exchange RPC Client Access service does not verify whether a variable is NULL before it accesses the variable.
To resolve this issue, install the following update rollup:
2579150 Description of Update Rollup 4 for Exchange Server 2010 Service Pack 1
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.