I can open your document in Writer and double click on it and PDF viewer opens and displays file just fine.
Up until now I have done all of the tests with launching attached Word document from e-mail. I see in this case LibreOffice opens the file in read only mode. When I double click on embed icon, nothing happens, no error nothing.
Now I have saved this file to disk and opened it with LibreOffice Writer, so file is in read & write mode. If I now click on PDF icon I get error: “Error activating object: General OLE error”. I see someone else has had this problem: Can't open an embedded .pdf file from .doc but with no solution provided how to fix the problem.
I can’t ask document owner to send some sample documents, because I have got this document from board of directors. They are too important, that I should nag with creating sample files.
I also do not use Microsoft Word, so I can’t test anything.
Work-around works fine: unzip file.