What is JotForm?
JotForm is a free online form builder which helps you create online forms without writing a single line of code. No sign-up required.
At JotForm, we want to make sure that you’re getting the online form builder help that you need. Our friendly customer support team is available 24/7.
We believe that if one user has a question, there could be more users who may have the same question. This is why many of our support forum threads are public and available to be searched and viewed. If you’d like help immediately, feel free to search for a similar question, or submit your question or concern.
Please take a look at the thumbnail of your theme again.
This is how it looks like now.
Thumbnails are automatically updated, so you probably saw the black screen on the YouTube video because the video was not loaded at that time.
Let us know if you are able to see it correctly now.