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HTTP Full Web Page sensor is “unable to navigate”. What can I do?



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When I use the HTTP Full Web Page sensor, I get the error message Unable to navigate (ERR_NAME_NOT_RESOLVED).

Where does this error come from? Are there any specific settings to consider regarding the computer on which my PRTG probe is running?

chromium error error-messages http http-full-web-page nla phantomjs prtg

Created on Mar 4, 2014 3:45:25 PM by  Gerald Schoch [Paessler Support]

Last change on May 21, 2019 12:57:24 PM by  Maike Guba [Paessler Support]

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This article applies to PRTG Network Monitor 19 or later

HTTP Full Web Page sensor: “Unable to navigate

The HTTP Full Web Page sensor can load web pages using one of the three browser engines Chromium, PhantomJS, or Internet Explorer. We recommend that you use the Chromium engine, but depending on your application scenario, one of the other engines might also be a reasonable choice.

If you added an HTTP Full Web Page sensor to PRTG but it does not work, check the following system settings and adjust them respectively. A typical error message for this sensor type is Unable to navigate (ERR_NAME_NOT_RESOLVED). Note that this message can also appear if PRTG cannot reach the given URL, so check this URL first.

System settings for the HTTP Full Web Page sensor

If you create an HTTP Full Web Page sensor, consider the following settings on the system that the probe with this sensor is running on:

Graphics card settings (Chromium and PhantomJS)

For the HTTP Full Web Page sensor, the settings of the graphics card on the machine with the PRTG probe are relevant. If you use, for example, an NVIDIA or ATI graphics card (and the following setting is available), disable the power-saving graphics processing unit (GPU) and use the high-performance processor instead.

See the article Google Chrome crashes when viewing maps. What can I do?, which describes where to change this option for NVIDIA. For ATI, you can select High Performance in the Catalyst control panel.

PRTG probe on Windows 7 (Chromium)

If your PRTG probe runs on a Windows 7 machine, there must be a Windows Experience Index. You need to scan this computer at least once for this index. Open the Windows control panel, select System | Check the Windows Experience Index, and start the scan.

Activate NLA

No matter which web browser engine you use, make sure that the NLA (Network Location Awareness) service is running. Open services.msc on the machine your PRTG probe is running on and start the NLA service if it is deactivated.

Created on Mar 4, 2014 3:49:50 PM by  Gerald Schoch [Paessler Support]

Last change on Dec 4, 2020 1:40:15 PM by  Brandy Greger [Paessler Support]

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Disclaimer: The information in the Paessler Knowledge Base comes without warranty of any kind. Use at your own risk. Before applying any instructions please exercise proper system administrator housekeeping. You must make sure that a proper backup of all your data is available.