The document with ID xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx can not be found (it probably has been deleted). The operation can not be completed.
This message will be displayed if you try changing the State of a new document that has not yet been saved. The Document ID has been allocated, but the document's details have not yet been written to the database (local or server). Save the document and then try again.
(There may be other reasons for this message; this is just one possibility.)