TinyMCE编辑器已停止在Wordpress中工作

在我的wordpress安装中，编辑器不再显示。我已经有一段时间没有更新WP了。我是4.8.15。一切正常。
在一篇帖子中，我有以下javascript错误：

GET http://www.myurl.net/wp-includes/js/tinymce/wp-tinymce.php?c=1&ver=4603-20170530 net::ERR_ABORTED 999 (No Hacking)
post.php?post=4709&action=edit:2716 

GET http://www.myurl.net/wp-includes/js/tinymce/wp-tinymce.php?c=1&ver=4603-20170530 net::ERR_ABORTED 999 (No Hacking)
post.php?post=4709&action=edit:2718 

Uncaught ReferenceError: tinymce is not defined
    at post.php?post=4709&action=edit:2718
(anonymous) @ post.php?post=4709&action=edit:2718
wp-langs-en.js?ver=4603-20170530:235 

Uncaught ReferenceError: tinyMCE is not defined
    at wp-langs-en.js?ver=4603-20170530:235
    at wp-langs-en.js?ver=4603-20170530:519
(anonymous) @ wp-langs-en.js?ver=4603-20170530:235
(anonymous) @ wp-langs-en.js?ver=4603-20170530:519
post.php?post=4709&action=edit:2713 

Uncaught ReferenceError: tinymce is not defined
    at Object.load_ext (post.php?post=4709&action=edit:2713)
    at post.php?post=4709&action=edit:2723