This article applies as of PRTG 22

Using HTTP Full Web Page sensor, Receiving error message : 

Unable to navigate (ERR_NAME_NOT_RESOLVED).

HTTP Full Web Page sensor: “Unable to navigate”

The HTTP Full Web Page sensor can load web pages via one of the three browser engines Chromium, PhantomJS, or Internet Explorer. We recommend that you use the Chromium engine, but depending on your case, the other engines can also be a good 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 is Unable to navigate (ERR_NAME_NOT_RESOLVED). Note that this error also appears if PRTG cannot reach the given URL, which is why you should check it 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 probe system:

Graphics card settings (Chromium and PhantomJS)

For the HTTP Full Web Page sensor, the settings of the graphics card on the probe system 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 instead use the high-performance processor.

To change this option for NVIDIA, see this article: Google Chrome crashes when viewing maps. What can I do?. For ATI, go to the Catalyst control panel and select High Performance.

Probe on Windows 7 (Chromium)

If your probe runs on a Windows 7 system, you must scan it at least once for the Windows Experience Index:

• Open the Windows control panel (click the Start button, then select Control Panel).
• Select System | Check the Windows Experience Index.
• Start the scan.

Activate NLA

No matter which web browser engine you use, make sure that the NLA (Network Location Awareness) service is running. To do so, open services.msc on the probe system and start the NLA service.