This could be the source of other bugs reported here.
We are getting a debug warning that breaks AJAX responses, even though WP_DEBUG is off. Here is a fix:
* Updated to use the fix suggested here: http://wordpress.org/support/topic/warning-while-using-wp-cli *
Version: 1.1, file jp-rm-jpmenu.php, line 36:
add_action( 'admin_init', 'jp_rm_menu' );
add_action( 'admin_menu', 'jp_rm_menu' );
The error we are seeing is in remove_menu_page():
<b>Warning</b>: Invalid argument supplied for foreach() in <b>.../wp-admin/includes/plugin.php</b> on line <b>1375</b><br />