Between the time I read this and now, a coworker had an issue with a short solid line showing up at the bottom of a document. We played around with it and finally determined it was the default separator below which footnotes would be placed. There were no actual footnotes in the doc, but perhaps someone had accidentally clicked on the button to add one, and it's not quite as simple as backspacing or highlighting and deleting to get the footnotes and the separation line out. You can try viewing your doc in Draft mode with Show ¶ turned on, and you'll possibly see a little superscript 1 which from there you can delete. Sorry if this is either the wrong guess or too little too late.

This page was of help to me in muddling through it:
Delete a footnote, endnote, or separator