Symptom
the Site Audit for a site has been stuck in the status: Crawling... 0 URLs found:
in the detailed view of the onpage analysis under Site Audit > Analysis management > example.tld, the value of the number of urls currently found in the crawl parameters area change after the detailed view is reloaded
Cause
A sitemap.xml exists on the domain, but cannot be called up.
Solution
With sitemap.xml:
Make sure that the sitemap.xml of the domain can be called up.
Without sitemap.xml:
If the sitemap.xml should not be accessible, configure the web server so that the HTTP error code 404 is returned when access is attempted.