We probably need more details about the problem. Is it an issue with the plug-in or a communication issue with the vinyl cutter/plotter? Is this a new setup or was your software and vinyl cutter/plotter working previously and then stopped working?
You will hae to contact Graphtec to see if they have plans to update the plugin to work with current version of Adobe Illustrator. There may also be other CAM software to drive the cutter that can either use Illustrator, EPS or SVG files. This is quite a normal CAM workflow to use teh design application to create the design and then use a websoftware or machine supplid driver to set speeds and feeds (and material specific settings) things that you would not do as a designer but are important for production/operator.