I keep getting messages that there is "one or more circular references" in nearly every spreadsheet

[MaryannaC]

This started a few days ago. In nearly EVERY spreadsheet I open that does not contain formulas I get the following message: "There are one or more circular references where a formula refers to its own cell either directly or indirectly. This might cause them to calculate incorrectly. Try moving or changing these references, or moving the formulas to different cells." This happens in spreadsheets I have opened recently and have had no problems with up until a few days ago. I have no idea what's causing the problem, or how to make it go away. I have completely shut down my computer and restarted everything (I know that's usually the first suggestion). Interestingly, spreadsheets that actually do contain formulas, have not shown this error message. The spreadsheets with the problems are all text -- weekly menus, new spreadsheet for workflow over the next few days. Stuff like that.

Help!
Thanks!!