[show selected signals] “API Link returned no Data”

[carlynvandyke]

When trying to retrieve a geo-level (e.g. County ADM 2) that doesn’t exist for a given signal (e.g. GFT), we get an error message “API Link returned no Data”. It should give a more informative message (e.g. ‘Signal Set “GFT” is not available at geo-level “County ADM 2”’ or even “Signal Set “GFT” is not available for location “Arizona”’).