Here is the displayed error page

I'm not sure if you got this resolved. I don't work for GoodData but I did just enable CORS for localhost. It looks like your GD workspace doesn't have CORS enabled for localhost. https://www.gooddata.com/developers/cloud-native/doc/cloud/manage-organization/set-up-cors-for-organization/ In your case I think you'd want to add

<https://localhost:8443>

as an allowed origin