Why does the data from the server come with null?

Question

AJAX

When requests from the browser, instead of string values, null is returned,



and if I send a request with curl, I get json with correct strings,



Headers set ( Accept: '*/*', 'Content-Type': 'application/json' , 'Accept-Language': ' * ',)
What could be the problem?

Answer 1

The problem could be anything on the server side, but obviously not the headers themselves. Because you still get a json response.
Look towards the server code which parses these headers. Perhaps there is one logic for some headers, and another logic for other headers (containing errors compared to the first logic). Maybe there is the simplest protection against parsing, etc. In general, it is necessary to look at the server code.