PHP Error in WP 3.9

After installing the plugin and while trying to work with it, these php error messages appear permanently. I can add new Buttons, but they don’t work. Immediate help is highly appreciated 🙂

Notice: Undefined index: content-block in /wp-content/plugins/visual-editor-custom-buttons/visual-editor-custom-buttons.php on line 714

Notice: Undefined index: row in /wp-content/plugins/visual-editor-custom-buttons/visual-editor-custom-buttons.php on line 721

Notice: Undefined index: custom_icon in /wp-content/plugins/visual-editor-custom-buttons/visual-editor-custom-buttons.php on line 754

Warning: Cannot modify header information - headers already sent by (output started at /wp-content/plugins/visual-editor-custom-buttons/visual-editor-custom-buttons.php:714) in /wp-includes/pluggable.php on line 1121

Notice:  Undefined variable: post in /wp-content/plugins/visual-editor-custom-buttons/visual-editor-custom-buttons.php on line 917

Notice:  Trying to get property of non-object in /wp-content/plugins/visual-editor-custom-buttons/visual-editor-custom-buttons.php on line 917

Notice:  Undefined variable: count in /wp-content/plugins/visual-editor-custom-buttons/visual-editor-custom-buttons.php on line 924

https://ww.wp.xz.cn/plugins/visual-editor-custom-buttons/