Why won’t the dry-erase marker not erase from my whiteboard?

Information on marker/pen compatibility

Please ensure that any whiteboard surface is a proper dry-erase surface before using it. You should be able to wipe away most marks with a damp cloth. If the mark still won’t come off with that, try drawing over the stubborn stain with a fresh dry erase marker. Once drawn over, you should be able to wipe it clean with a cloth. Please note that the marker you use for cleaning will pick up some of the color you are drawing over, so use a darker marker to clean if possible.