SPException:The file abc.doc has been modified by on at Microsoft.SharePoint.Library.SPRequestInternalClass.AddOrUpdateItem(String bstrUrl, String bstrListName, Boolean bAdd, Boolean bSystemUpdate, Boolean bPreserveItemVersion, Boolean bUpdateNoVersion, Int32& plID, String& pbstrGuid, Guid pbstrNewDocId, Boolean bHasNewDocId, String bstrVersion, Object& pvarAttachmentNames, Object& pvarAttachmentContents, Object& pvarProperties, Boolean bCheckOut, Boolean bCheckin, Boolean bMigration, Boolean bPublish)

This error occurs when you upload a file to a document library through the SharePoint UI and when the document library has an event receiver which updates the list item on ItemAdded(). The error doesn’t happen all the time (for instance, it happened only on our Prod) which lead us to conclude that it is due to some race conditions, especially knowing that event receivers are run in separate thread.

The error message is “The file … has been modified by … on ….” and the callstack leads to a COMException in the Microsoft.SharePoint.Library assembly, which is the managed wrapper of OWSSVR.dll. The full stacktrace looks something like this:

[COMException (0x81020037): The file abc.doc has been modified by on ]
at Microsoft.SharePoint.Library.SPRequestInternalClass.AddOrUpdateItem(String bstrUrl, String bstrListName, Boolean bAdd, Boolean bSystemUpdate, Boolean bPreserveItemVersion, Boolean bUpdateNoVersion, Int32& plID, String& pbstrGuid, Guid pbstrNewDocId, Boolean bHasNewDocId, String bstrVersion, Object& pvarAttachmentNames, Object& pvarAttachmentContents, Object& pvarProperties, Boolean bCheckOut, Boolean bCheckin, Boolean bMigration, Boolean bPublish) +0
at Microsoft.SharePoint.Library.SPRequest.AddOrUpdateItem(String bstrUrl, String bstrListName, Boolean bAdd, Boolean bSystemUpdate, Boolean bPreserveItemVersion, Boolean bUpdateNoVersion, Int32& plID, String& pbstrGuid, Guid pbstrNewDocId, Boolean bHasNewDocId, String bstrVersion, Object& pvarAttachmentNames, Object& pvarAttachmentContents, Object& pvarProperties, Boolean bCheckOut, Boolean bCheckin, Boolean bMigration, Boolean bPublish) +411

[SPException: The file abc.doc has been modified by on ]
at Microsoft.SharePoint.Library.SPRequest.AddOrUpdateItem(String bstrUrl, String bstrListName, Boolean bAdd, Boolean bSystemUpdate, Boolean bPreserveItemVersion, Boolean   bUpdateNoVersion, Int32& plID, String& pbstrGuid, Guid pbstrNewDocId, Boolean bHasNewDocId, String bstrVersion, Object& pvarAttachmentNames, Object& pvarAttachmentContents, Object& pvarProperties, Boolean bCheckOut, Boolean bCheckin, Boolean bMigration, Boolean bPublish) +556
at Microsoft.SharePoint.SPListItem.AddOrUpdateItem(Boolean bAdd, Boolean bSystem, Boolean bPreserveItemVersion, Boolean bNoVersion, Boolean bMigration, Boolean bPublish, Boolean bCheckOut, Boolean bCheckin, Guid newGuidOnAdd, Int32& ulID, Object& objAttachmentNames, Object& objAttachmentContents, Boolean suppressAfterEvents) +3030
at Microsoft.SharePoint.SPListItem.UpdateInternal(Boolean bSystem, Boolean bPreserveItemVersion, Guid newGuidOnAdd, Boolean bMigration, Boolean bPublish, Boolean bNoVersion, Boolean bCheckOut, Boolean bCheckin, Boolean suppressAfterEvents) +632
at Microsoft.SharePoint.SPListItem.UpdateOverwriteVersion() +190
at Microsoft.SharePoint.WebControls.SaveButton.SaveItem(SPContext itemContext, Boolean uploadMode, String checkInComment) +256
at Microsoft.SharePoint.WebControls.SaveButton.SaveItem() +111
at Microsoft.SharePoint.WebControls.SaveButton.OnBubbleEvent(Object source, EventArgs e) +476
at System.Web.UI.Control.RaiseBubbleEvent(Object source, EventArgs args) +50
at System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) +39
at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +3215

Fix:

one way to fix the problem is changing your event receiver to update the list item using item.SystemUpdate(false) instead of item.Update(). Some people recommend to disable the event firing when calling the Systemupdate:

this.DisableEventFiring();

try

{

      item.SystemUpdate(false);

}

finally

{

      this.EnableEventFiring();

}