Visual drag and drop plug in

My thee requires the visual drag and drop plug in. When I try to install it I get an error message that says “no valid header.” Please help.Also – I paid $150 for a guaranteed 15 minute call back. I got a call in about 10 minutes. There was a ton of background noise and before anyone ever said anything, the call was disconnected. No one attempted to call again, and when I tried the number it did not go through.