Elm http request returns NetworkError for successful requests

For a quick solution while developing you can use the CORS everywhere extension for firefox and add the following to your whitelist in the extension preferences:

/^https?...localhost:8888\//i

For chrome you can probably use this extension

@Sidney and @SimonH,

Thank you for looking into this for me, I feel bad because this wasn't an Elm issue after all.

The solution ended up using a CORS middleware on the server to add the 'Access-Control-Allow-Origin' header. The server was still responding with a 200 status and even included the entire successful response body but this resulted in a failure in Elm's Http Result.

Thank you again for your time and thought!