Although the app is saying “An invalid API key has been detected” the reality is the error is being thrown because WUnderground is giving an error. The line of code specifically triggering the error you are seeing is below:
if (typeof data.response.error === “object”) {
showerror(_(“An invalid API key has been detected”));
return;
}
This means it WUnderground returns data with an error then the app stops processing the request and shows the message.
The reality is, this can be due to your API key having no more calls for that day or it could be the location is not valid. In order to debug this, I would navigate directly to WUnderground by using the below URL to discover the actual error:
http://api.wunderground.com/api/APIKEY/yesterday/conditions/q/LOCATION.json
Change the APIKEY to your WUnderground API key and LOCATION to the location you have provided in the location box on the options page. Once we have the actual error we can troubleshoot from there.
Thank you