TypeError: Failed to execute 'fetch' on 'Window': Invalid value

Question

I\'ve tried to use fetch to call from backend using react, without libs (such as Axios). So I created this function:

export function api(url, method, body, i         


        

Answer 1

This also happened to me when I tried to add an Authorization header to my fetch calls. In my case it was caused by a newline character in the header string, i.e. Bearer:\nsomelong-token. Changing the new line to a space solved the problem.