When this issue occurs, event ID 4999 that resembles the following is logged in the Application log:
Log Name: Application
Source: MSExchange Common
Description: E12, BuildType, ApplicationVersion, MERpcClientAccess Service, MEData.Storage, MEDSAcrPropertyBag.OpenPropertyStream, System.InvalidOperationException, xxxx, . Version Number
To resolve this issue, install the following update rollup:
Update Rollup 6 for Exchange Server 2010 Service Pack 3
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.