When you start Site Viewer up on showing a txsite or rxsite object, a check is made to make sure that you have an internet connection to retrieve the default basemap and terrain data.
If Site Viewer cannot connect to the Internet the following warning messages are displayed:
Warning: Unable to access the Internet, showing Dark Water instead of Satellites. See Access Basemaps and Terrain in Site Viewer.
Warning: Unable to access terrain data. See Access Basemaps and Terrain in Site Viewer.
If Site Viewer cannot connect to the Internet, then terrain data is not used and the "Dark Water" basemap is selected.
Site Viewer can fail to open because of two reasons:
In MATLAB®, OpenGL® is set to software graphics. An error message is displayed in the command window, notifying you to upgrade the graphics hardware driver or select hardware graphics using OpenGL.
For more information, see Resolving Low-Level Graphics Issues (MATLAB)