Enfold update 3.8.5 gives problem with handling custom avia shortcodes

Hi I have a question. My website online has the enfold version 3.8
in order to work on some custom pages and do some tests I downloaded my website on my local pc. In the meanwhile I updated the theme (locally only) to enfold 3.8.5

I realized that if I keep my custom shortcode in the child theme it gives problems in adding new pages: whenever I update a new page or I try to delete it, a completely blank screen appears, although it actually saves or bin the pages (i.e. the action is completed successfully). Trying to understand what was messing up, I realized that everything worked fine if I deleted the shortcode folder in my child theme.

At this point, before updating the online enfold theme I would like to understand if you are aware of such bugs. The shoertcode I created was very simple, as it only applied the <abbr> tag to the text. herebelow I copy my code:

if ( !class_exists( 'av_abbr' ) )
{
	class av_abbr extends aviaShortcodeTemplate
	{
			/**
			 * Create the config array for the shortcode button
			 */
			function shortcode_insert_button()
			{
				$this->config['name']			= __('Acronym Extension');
				$this->config['order']			= 100;
				$this->config['shortcode'] 		= 'av_abbr';
				$this->config['tooltip'] 	    = __('Creates a full text which appears on mouse over acronyms terms');
				$this->config['inline'] 	= true;
				$this->config['tinyMCE']    = array('tiny_always'=>true);
			}

			/**
			 * Popup Elements
			 *
			 * If this function is defined in a child class the element automatically gets an edit button, that, when pressed
			 * opens a modal window that allows to edit the element properties
			 *
			 * @return void
			 */
			function popup_elements()
			{
				$this->elements = array(
					
					array(
							"type" 	=> "tab_container", 'nodescription' => true
						),
						
					array(
							"type" 	=> "tab",
							"name"  => __("Content" , 'avia_framework'),
							'nodescription' => true
						),
					array(	"name" 	=> __("Acronym", 'avia_framework' ),
							"desc" 	=> __("This is the acronym.", 'avia_framework' ),
				            "id" 	=> "acronym",
				            "type" 	=> "input",
				            "std" => __("ACR", 'avia_framework' )),
					
					array(	"name" 	=> __("Full title", 'avia_framework' ),
							"desc" 	=> __("This is the text that appears on your acronym.", 'avia_framework' ),
				            "id" 	=> "title",
				            "type" 	=> "input",
				            "std" => __("Full text", 'avia_framework' )),
					array(
							"type" 	=> "close_div",
							'nodescription' => true
						),
						
				);

		}

			/**
			 * Frontend Shortcode Handler
			 *
			 * @param array $atts array of attributes
			 * @param string $content text within enclosing form of shortcode element
			 * @param string $shortcodename the shortcode found, when == callback name
			 * @return string $output returns the modified html string
			 */
			function shortcode_handler($atts, $content = "", $shortcodename = "", $meta = "")
			{
				$output = "";

				$atts = shortcode_atts(
						array(	'title'=>'',
								'acronym' =>'', 
							), $atts, $this->config['shortcode']);
				

			
				$output = '';
				
				$output= "<abbr title='".$atts['title']. "'> " . $atts['acronym'] . "</abbr>";

				//<abbr title = 'xx'>ACR</abbr>
				
				return $output;
			}

	}
}

Thanks very much