How to capture 500 and other 5xx server errors with URLToImage?

I am using the code simillar to https://grabz.it/api/aspnet/advanced/com-object/. The catch handler does catch the 404 error with this returned message "You are trying to take a screenshot of a URL that does not exist! Please enter a URL that is both absolute and public, for instance: http://www.example.com". However when there is a server error, the code still goes through and the image captured is of a Server Error web page. Is there a way for URLToImage to also flag those errors?

This message "You are trying to take a screenshot of a URL that does not exist! Please enter a URL that is both absolute and public, for instance: http://www.example.com" is not a 404 error. This occurs for invalid URL formats and if the domain does not exist.

As long as those two criteria are met we capture whatever is found.