React blank page with build

Hi,

I'm pretty new to React(and new here), been learning it. Created a project - npm create vite@latest.... and put a project together. Now when I run the dev version it works just fine. However if I do the run build, and then go to the folder dist and open the index.html file, I just get a blank page.

So I do an inspect on the page and if Firefox I get this error message -
"Cross-Origin Request Blocked: The Same Origin Policy disallows reading from the remote resource at file:///assets/index-J7cny882.js (Reason: CORS request not http)"

This message appears 4 times. Twice with the same "file:///assets/index-J7cny882.js" and the other two with this "file:///assets/index0BAXWxR6k.css"

I'm a bit puzzled by this.

Thanks.