Do you've ProjectHook class attached to your Project?

>I have been working on a project for a few weeks now and have been doing a Build regularly to make sure that no errors show up as I continue through the project. Now, all of the sudden, when I go to open the project or build it, VFP comes up with error messages stating: "Variable 'mvar' is not found." It does this for 3 different variables. I recognize the variable names as ones that I have used in the project, but I've never seen this problem before and don't know anything that I've changed to make this occur. I've tried doing a Project Rebuild, but I still get the error messages. Would greatly appreciate any help in alleviating this problem. TIA.