I am seeing the following in the event log. Anybody have any ideas short of calling Microsoft. I am seeing hundreds created per minute on our OWA server. Log Name: Application Source: MSExchange Web Services Date: 2/7/2011 1:37:42 PM Event ID: 3 Task Category: Core Level: Error Keywords: Classic User: N/A Computer: cas.company.com Description: An internal server error occurred. The unhandled exception was: Microsoft.Exchange.Data.Storage.RecurrenceFormatException: Incomplete recurrence binary large object (BLOB). at Microsoft.Exchange.Data.Storage.InternalRecurrence.ReadExceptionInfoSubstring(BinaryReader blobReader, Int32 usingCodePageId) at Microsoft.Exchange.Data.Storage.InternalRecurrence.ParseExceptionInfo(BinaryReader blobReader, RecurrenceVersion recurrenceVersion, Int32 usingCodePageId) at Microsoft.Exchange.Data.Storage.InternalRecurrence.InternalParse(Byte[] blob, Item masterItem, VersionedId masterItemId, ExchangeTimeZone organizerTimeZone, ExchangeTimeZone userTimeZone, Boolean expectNoException, Int32 usingCodePageId) at Microsoft.Exchange.Data.Storage.InternalRecurrence.InternalParse(Byte[] blob, Item masterItem, ExchangeTimeZone organizerTimeZone, ExchangeTimeZone userTimeZone, Int32 usingCodePageId) at Microsoft.Exchange.Data.Storage.CalendarItem.GetRecurrenceFromItem(Item item) at Microsoft.Exchange.Data.Storage.VCalendar.DemoteProperties() at Microsoft.Exchange.Data.Storage.VCalendar.Demote(CalendarWriter calendarWriter) at Microsoft.Exchange.Data.Storage.CalendarDocument.ItemToICal(Item item, OutboundAddressCache addressCache, Stream stream, String charsetName, OutboundConversionOptions outboundConversionOptions) at Microsoft.Exchange.Data.Storage.ItemToMimeConverter.WriteMimeBody(MimePartContentType contentType, MimeFlags flags) at Microsoft.Exchange.Data.Storage.ItemToMimeConverter.StaticWriteMimeBody(ItemToMimeConverter converter, 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, MimeFlags flags) at Microsoft.Exchange.Data.Storage.ItemConversion.<>c__DisplayClassf.<InternalConvertItemToMime>b__e() at Microsoft.Exchange.Data.Storage.ConvertUtils.CallCts(Trace tracer, String methodName, String exceptionString, CtsCall ctsCall) at Microsoft.Exchange.Data.Storage.ItemConversion.ConvertItemToMime(Item itemIn, Stream mimeOut, OutboundConversionOptions options) at Microsoft.Exchange.Services.Core.DataConverter.MimeContentProperty.ConvertItemToMime(Item item, Stream mimeContentStream, OutboundConversionOptions outboundConversionOptions) at Microsoft.Exchange.Services.Core.DataConverter.MimeContentProperty.WriteMimeContent(XmlWriter writer, Object item, Object buffer) at System.Xml.XmlElement.WriteContentTo(XmlWriter w) at System.Xml.XmlElement.WriteTo(XmlWriter w) at System.Xml.XmlElement.WriteContentTo(XmlWriter w) at System.Xml.XmlElement.WriteTo(XmlWriter w) at Microsoft.Exchange.Services.Core.Types.ResponseNodeArray.WriteAllNodes(XmlWriter writer) at Microsoft.Exchange.Services.Core.Types.ResponseNodeArray.InternalWriteXml(XmlWriter writer) at Microsoft.Exchange.Common.IL.ILUtil.DoTryFilterCatch(TryDelegate tryDelegate, FilterDelegate filterDelegate, CatchDelegate catchDelegate)

Hi R2011, Which version of Exchange server do your run? Exchange 2007 or 2010? Suggest you install the latest service pack and rollup in order to avoid some known issues. Is there any error message when users open OWA? Please run the Exbpa to do a system check. If possible, please reset the OWA virtual directory to test.Please remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

Hi R2011, Any updates?Please remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.