I would like to see a snapshot of any error pages when either verifying the script or during test execution as part of logging. Is this available?
NeoLoad works at protocol level. That means he will replay your HTTP requests but during a test it will not render the HTML pages like a client browser can do.
That's why it can provide any screen shot image during test execution. But during a check virtual user, it can render the HTML page. So you should be able to see the error page but still no snap shot.
Let me know if i did not understand your question.