From your post, all I get about your issue is in the title: “No Video Signal”. The rest of your post doesn’t seem to address what is going on with the current experience with this software. It would be helpful if you could elaborate about you setup, which steps you took, etc.
You seem to want to exclude hardware from your investigation. How would you know if the capture device was damaged or not?
Easy VHS to DVD 1.0.5 is from June 2011, when developers were making apps for 10.6 Snow Leopard and in anticipation of 10.7 Lion a few weeks later. This application has been reported to work, without dispute, with 10.7 and 10.8, but unknown for other OSs, on Roaring Apps. Roxio’s own system requirements list only Mac OS X 10.4, 10.5 or 10.6. I feel that Roxio should have tested later OS versions, as they still offer the product today.
Any 32-bit application will get the warning in High Sierra 10.13.4 or later. And it is a warning (about Apple’s plans for the future), not an error. However, the OS publisher (Apple) has no obligation to keep supporting all applications unchanged forever in later versions of the OS. There are other changes in the OS that might break compatibility with some older software; that would be conceivable. Some applications need updates for newer operation systems, but Roxio has not shown any effort in this regard, nor made any statement if such is needed or not.