What is this error?

[Exchange Web Services]Synchronizing folder '[email protected]/Inbox' failed due to the following error: Unexpected end of file has occurred. The following elements are not closed: t:Content, t:FileAttachment, m:Attachments, m:GetAttachmentResponseMessage, m:ResponseMessages, m:GetAttachmentResponse, s:Body, s:Envelope. Line 1, position 2408568.