You are doing nothing wrong. The problem is at our end. It was brought to my attention last week. I reported it to the support staff. They fixed it. There is at least one run from last Friday that ran to completion. Today, I note that it is down again! This is very frustrating, because the bug has nothing to do with our software. It is a bug in an external application that creates the images in png and jpg format. We will solve it as soon as possible. Thank you for reporting the problem.