Our tests seem fine.
There may be some problem with your application. This message is now shown if the server has to generate several documents. For example, if you have several business objects in the context and you ask to generate the MS Word document, the server will generate several documents - one for each instance of the object. But it will not display several documents and will generate this error message instead.
Previously it used to display the first document. Check how many instances of the object there are in the context.