Symptoms
Under Onpage > Analysis management > example.tld the message Error start URL is displayed
the following string is in the source code of the page:
<meta name="robots" content="noindex,nofollow">
Cause
The meta tag robots prevents the page from being crawled.
Solution
Remove noindex, nofollow from the meta tag robots
Restart the onpage analysis by navigating to Onpage > Analysis management > example.tld and clicking on START RECRAWL .