I can't figure out why the zoom tool is greyed out all of a sudden. I've tried all the view option and none of them just give me a simple one-page document displayed large enough for me to read. When I go the View/zoom the tool is greyed out, I've never experienced that before. Something has changed and I can't figure out what.

In the past, I have always been able to open my document, click the zoom tool, set the percent of zoom, and my document enlarged. Now that process doesn't work.