Why, after connecting the Bitrix core in ajax.php, an empty result always comes in the response?

Question

AJAX

From the js file I make a fetch request to ajax.php. now it looks something like this:

require($_SERVER["DOCUMENT_ROOT"]."/bitrix/modules/main/include/prolog_before.php");
echo json_encode(array); //

Actually the question is: why, when requesting this file without connecting the kernel, the desired answer comes, and if you connect the kernel, then an empty response comes?

Answer 1

Because there is probably a mistake somewhere.
Bitrix hides errors behind a white screen. Set DEBUG=true in the config and see what it says.
Well, or look in the logs
https://dev.1c-bitrix.ru/support/forum/forum6/topi...
https://blog.sokov.org/bitrix-console/