"Error! Cannot write to Info.plist. There are permission problems, or you are on a read-only volume. This cannot run from within a read-only dmg file."

The message you get is because you have not placed the file in the application folder. The software can't be run without being installed as an application which you do by selecting the SignCut Pro 2 software together with SignCut Draw and then drag and drop it in the application folder (open in a separate finder window).