Q: I am trying to upload  a resume from documents on my mac book pro and keep getting message file has no pages

I have a Mac Book Pro and suddenly, when I try to attach my resume to an employers website, I get a message saying, " the document you are attempting to upload is empty" or, "Document format to upload is not supported," or, uploading document has no pages.  I have never had this problem before,  When I attach the same files to my email, it works fine.  Please help!!!!  I am looking for employment and have to do it online.