I posted on WP forum a week ago, but no one answers.

[Thu Mar 15 11:17:40.299034 2018] [allowmethods:error] [pid 23959:tid 140642478888704] [client my-ip-address:2809] AH01623: client method denied by server configuration: 'PUT' to /home/username/domains/my-domain/public_html/wp-json, referer: http://my-domain/wp-admin/post-new.php?post_type=page
With version 2.4.0, still get the same error when creating a new page then save.