How come under the Data tabs "which forecast to use" has different options then under the Dark Sky alternatives in the API tab?
The current solution:
Data tabs: The DarkSky Forecast scripts are still the same as before. They expect forecast data in the original DarkSky format.
API tab: As the original DarkSky does not work anymore you have to select another provider of "compatible with DarkSky" data
Either OpenWeatherMap, VirtualCrossing or PirateWeather
The load data scripts convert the data from the selected one into the original format for the DarkSky scripts.
In your case you selected on the data tab "WeatherUnderground" for your forecast
Then you should set the contents "Darksky and alternatives after March 31, 2023"
=> "Select which alternative . . ." to "Not used"
=> and empty the field labeled "API Key for forecast . . . "
Succes,
Wim