Some of you may have experienced problems trying to create field configurations for NTRIP-based sources (e.g., VRS or single base). Specifically, you receive an ‘Error retrieving the list of sources‘ message a short time after clicking the ellipses button next to the ‘NTRIP Source’ entry box and no mount points will be displayed in the list.
The underlying problem has to do with how the standard .NET methods in Positions Desktop try to parse the headers in the NTRIP response. Since the response may not include true HTTP headers, it tries to parse the NTRIP headers instead as though they were HTTP headers and therein lies the problem. Ironically, the presence of a proxy server in your network environment resolves the issue since it injects real HTTP headers in the response.
We’re working to resolve this in the next release, but there is a workaround that can be employed now. Locate the ArcMap.exe.config file (e.g., C:\Program Files (x86)\ArcGIS\Desktop10.1\bin) and edit it to add a <system.net> section at the bottom (after the closing </runtime> tag and before the closing </configuration> tag):
</runtime> <system.net> <settings> <httpWebRequest useUnsafeHeaderParsing="true" /> </settings> </system.net> </configuration>
For those of you so inclined, there are numerous articles out there about this general .NET option.