string. Present only when status is error. Machine-readable reason: http, not-html, too-large, timeout, network, dns, blocked, platform, invalid-url, redirects, host-refused, robots-unavailable, extract-failed, extract-timeout, too-deeply-nested, bot-challenge (a bot-check or block page: free, never worked around), slow-host (robots.txt asks for a Crawl-delay over the 1.75 s maximum this Actor honours: free), not-processed (the run's time limit was reached before the page could be fetched or converted: free), row-too-large (the converted page does not fit in one dataset row: free), push-failed and sitemap codes.