The configuration for SignCut has changed or is damaged. Please try to do the following instructions below to clear the application data which is basically a hard reset for SignCut.
This will reset SignCut so you will lose your cutting plotter settings and license number in the program. If you aren't sure what settings to use and are able to start SignCut, I recommend you to click "Cutter" in the settings menu and write down what you have selected for manufacturer, cutter, output device and baud. Then close that dialogue and click "About SignCut" in the help menu and write down your license number.
Please close SignCut then follow these steps to clear the app data.
1. Open finder.
2. Click on "Go to folder" in the Go menu.
3. Write ~/library in the box and click Go.
4. Open the Application Support folder.
5 Locate all SignCut folders and delete them.
6. Open finder again and click "Home" in the Go menu.
7. Locate a file called SignCut.ipc and delete it (if you do not find it move on to the next step).
8. Restart SignCut and enter your license number and cutter settings.
9. Close the program then restart it and all your information you entered should be saved in the program.
Here you have a video that shows the process: http://www.youtube.com/watch?v=DLuqIEGS7BA