Adobe Acrobat DC is putting everything on a blue checkerboard background.

I have an issue which has just arisen. When I save a Microsoft Word document (Word 2010) document which is simply text on a white background as a PDF document the PDF document is no longer on a white background. It is now on a blue checkerboard background. This also happens if I print the document as a PDF document. It also happens if I scan the word document into PDF format.