Paragraphs gone

In editing mode paragraphs are gone and hitting “enter” duplicates “div” instead of creating another paragraph.

I think that it may be happening somewhere here:

public function the_content( $content ) {

	global $post;

	$content = $post->post_content;
	$content = str_replace( '<!--nextpage-->' , esc_html( '<!--nextpage-->' ) , $content );
	$content = '<div id="fee-edit-content-' . $post->ID . '" class="contenteditable">' . $content . '</div>';

	return $content;

}

http://wordpress.org/plugins/wp-front-end-editor/