Symptoms
In a Microsoft Exchange Server 2013 environment, messages are stuck in the Submission queue until nondelivery report (NDR) messages are returned or the server is restarted. Additionally, the following exception is logged in the message tracking logs:
Microsoft.Exchange.Data.Storage.OleConversionServerBusyException: OLE conversion failed ---> Microsoft.Exchange.ProcessManager.ComInterfaceInitializeException: Work process exit before class id registered! at Microsoft.Exchange.ProcessManager.ComProcessAgent`1.InternalLaunchWorkProcess(OnCreateWorker createWorker, Object requestParameters) at Microsoft.Exchange.ProcessManager.ComProcessAgent`1.LaunchWorkerProcess(OnCreateWorker createWorker, Object requestParameters) at Microsoft.Exchange.ProcessManager.ComProcessManager`1.ExecuteRequest(Object requestParameters) at Microsoft.Exchange.Data.Storage.OleConverter.ConvertToBitmap(Stream oleDataStream) --- End of inner exception stack trace --- at Microsoft.Exchange.Data.Storage.OleConverter.ConvertToBitmap(Stream oleDataStream) at Microsoft.Exchange.Data.Storage.OleAttachment.ConvertToBitmap() at Microsoft.Exchange.Data.Storage.OleAttachment.ConvertToImage(Stream outStream, ImageFormat format) at Microsoft.Exchange.Data.Storage.OleAttachment.TryConvertToImage(Stream outStream, ImageFormat format) at Microsoft.Exchange.Data.Storage.ItemToMimeConverter.WriteMimeStreamAttachment(StreamAttachmentBase attachment, MimeFlags flags) at Microsoft.Exchange.Data.Storage.ItemToMimeConverter.WriteMimeAttachment(MimePartInfo part, MimeFlags flags) at Microsoft.Exchange.Data.Storage.ItemToMimeConverter.WriteMimePart(MimePartInfo part, MimeFlags mimeFlags) at Microsoft.Exchange.Data.Storage.ItemToMimeConverter.WriteMimeParts(List`1 parts, MimeFlags mimeFlags) at Microsoft.Exchange.Data.Storage.ItemToMimeConverter.WriteMimePart(MimePartInfo part, MimeFlags mimeFlags) at Microsoft.Exchange.Data.Storage.ItemToMimeConverter.ConvertItemToMimeInternal(MimeStreamWriter writer, ConversionLimitsTracker limits)
Cause
This problem occurs because of handle leaks that cause the OleConversionServerBusyException exception in the transport.
Resolution
To fix this problem, install Cumulative Update 12 for Exchange Server 2013 or a later cumulative update for Exchange Server 2013.
Status
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
References
Learn about the terminology that Microsoft uses to describe software updates.
