Why do I get an error screenshot for a working web page or website?
There could be many reasons for receiving an error instead of the expected screenshot. First, though, you should make sure that the URL really is working. We've even seen a number of situations where a web page was working from one country but not outside that country (routing issues outside of our networks, web page misconfiguration, geo-blocking, etc). If you know that the page should load, here are a few of the more common reasons for failure:
- Transient routing issues between our datacenter(s) and the remote web server that is hosting the page to capture. The errors associated with this scenario tend to be NS_ERROR_NET_ABORT, NS_ERROR_NET_TIMEOUT, NS_ERROR_CONNECTION_CLOSED, etc. There isn't much we can do about these issues, unless it is due to our datacenter's upstream providers. If we capture the page intermittently, from some of our datacenters but not others, then we can submit a support ticket to the affected datacenter(s). We capture from multiple locations/datacenters, so investigating these failures could take several days to coordinate with our datacenters and their upstream providers.
- Remote web server misconfiguration can also result in the errors listed above. These issues are outside of our control. You must contact the remote site owner.
- Remote web server uses a bot filter that is too aggressive. If our script is detected as a "bot", it may be filtered out as a "site scraper", "malicious bot", etc. The errors related to this scenario tend to be NS_ERROR_ACCESS_DENIED (which "may" capture the error page), HTTP:403 (which will capture the error page), NS_ERROR_NET_ABORT, NS_ERROR_CONNECTION_REFUSED, etc.
- Remote web server uses a firewall or DDoS or bot filter that requires a CAPTCHA entry to proceed. Some services, such as "SiteLock" will detect our scripts and request a CAPTCHA to verify "human access". Since we have a policy not to employ automated solutions to bypass access prevention safeguards, these captures will fail. The error code is typically BLANK_DETECTED or TOO_MANY_ATTEMPTS.
As we always strive to overcome any obstacle preventing automated web page screenshot capture, we invite any user to notify us of known "good" URLs that will not capture properly. In many cases, we have no control over the reason for the failure, but we will do our best to remove the obstacle, when possible.