grozniy

yes, I have fixed when deactivated official Facebook plugin for WP. Thanks!

this problem aslo actual for 3.8.1
I solved it:
add few lines to wp-settings.php

require( ABSPATH . WPINC . '/date.php' ); // to 114 line
require( ABSPATH . WPINC . '/revision.php' ); // to 125
require( ABSPATH . WPINC . '/post-formats.php' ); // to 126
require( ABSPATH . WPINC . '/class-wp-embed.php' ); // to 144