Hi,
You are a victim of a security feature called XSS or Same Origin Policy (ERR_BLOCKED_BY_CLIENT) Same-origin policy - Wikipedia, the free encyclopedia
It prevents javascript from dynamically loading data from different domain/port to the current web-server. In real life this is a great thing as you know the content is actually from the site you are visiting, for developing this can be a real pain!
Luckily there are a couple of workarounds for this depending on what you are doing. It looks like you are running a local web server of some kind and they are usually capable of reverse proxying something on localhost/.. to a remote server.
Let me know what you're using and maybe I can help further.
Oli