Random Unity Errors I can't get rid of

I downloaded 2 fps packs yesterday (that took 2 years to install) and now I have 3 errors that seem to be related to the fps control pack. Here is a screenshot of the errors: Screenshot by Lightshot

I clicked on the script to find it but I did ctrl + f “constructor” and got nothing, so I don’t understand what it is referring to or how to fix it.

Hello,

Replace lines 107 to 123 in ProGrids_GUI.js with this:

        if(GUILayout.Button(GUIContent(snapSizeGraphic as UnityEngine.Texture, "Change the Grid Size and Units")))
        {
            EditorUtility.DisplayDialog("Grid Size and Units", "Grid size and units are adjustable at any time! Meters, Centimeters, Feet, and Inches are available. Sorry, not available in the Free Version.", "Okay");
        }

        //show angles on/off toggle
        if(GUILayout.Button(GUIContent(anglesOffGraphic as UnityEngine.Texture, "Toggle Angles Visibility On/Off")))
        {
            EditorUtility.DisplayDialog("Angle Guidelines", "You can view handy Angle Guidelines for precise construction. Sorry, not available in the Free Version.", "Okay");
        }

I got this from this link FPS Forum

They have a long discussions for this error.