Take a look in the Errors tab to see if there are any errors. If you experience any power brownouts, this can cause a communication error where the generator gets stuck. To prevent this, you need to buy an Uninterruptible Power Supply, to keep things working if there is a brownout.
If your system is stuck, shut down the software, unplug the generator from the machine, restart the generator, plug the generator into the computer and restart Spooky.
At the bottom of your screen take note of the area I've highlighted in yellow (click the picture to enlarge).
If these numbers go up you have a problem and should head over to the Errors Tab to see what is going on.
If you want more details, please check the link: