EWS C# problem with attachments and Processed folder

I have the next problem: The specified object was not found in the store.

" в Microsoft.Exchange.WebServices.Data.ServiceResponse.InternalThrowIfNecessary()\r\n в Microsoft.Exchange.WebServices.Data.ServiceResponse.ThrowIfNecessary()\r\n в Microsoft.Exchange.WebServices.Data.MultiResponseServiceRequest1.Execute()\r\n в Microsoft.Exchange.WebServices.Data.ExchangeService.InternalGetAttachments(IEnumerable1 attachments, Nullable1 bodyType, IEnumerable1 additionalProperties, ServiceErrorHandling errorHandling)\r\n в Microsoft.Exchange.WebServices.Data.ExchangeService.GetAttachment(Attachment attachment, Nullable1 bodyType, IEnumerable1 additionalProperties)\r\n в Microsoft.Exchange.WebServices.Data.Attachment.InternalLoad(Nullable1 bodyType, IEnumerable1 additionalProperties)\r\n в Microsoft.Exchange.WebServices.Data.Attachment.Load()\r\n в Microsoft.Exchange.WebServices.Data.FileAttachment.Load(Stream 开发者_开发问答stream)\r\n в exm.Program.Main() в D:\exm\exm\Program.cs:строка 406"

I have read that it may be caused of moving item, and that's why ID is dynamically changing! But, I didn’t make any changing at in “foreach” I'm getting attachments and Load it to Stream and only after it moving, but exception I caught when I load stream and I don't even get to MoveItem() , I caught exception earlier...

Also, I don't understand what is “Processed” folder? I can't see it in "WellKnownItems" enumeration.

Ews library doesn't work well, if you have rather old outlook exchange server, for example, this lib works very bad with 2007 version, but good with 2010, some methods really don't work in this lib, as for me it's better not to use this lib, try to find some 3-rd party lib, which is very good and people use it or try to learn network programming on lower level (tcp/ip) and then build each request manually and not using this lib, of course there could be some problems , if your system administrator disabled POP/IMAP/SMTP methods to get/send mails and give you only OWA or LDAP access to mailboxes...