Hello all,
I faced the same issue & i solved it by
First deactivate all the plugins and check the jetpack, for max people this is solved by deactivating the other plugins
If this won’t work for you
Go-to wp-config.php file change and change WP_DEBUG to false and reload, it may work
define(‘WP_DEBUG’, false);
Finally check xmlrpc.php which is located on root directory, any white spaces in the code.