After upgrade, hamburger menu not working

My preference would be to no display the hamburger menu at all on the desktop.
Lyse

Hi Victoria,

I have not updated the file you mentioned because I didn’t know it had changed. When I compare both files files I see a number of differences.

There are:
JUST BEFORE THE: //subheader, only display when the user chooses a social header
I HAVE THIS CODE:

if($responsive)
{
	echo '<a id="advanced_menu_toggle" href="#" '.av_icon_string('mobile_menu').'></a>';
	echo '<a id="advanced_menu_hide" href="#" 	'.av_icon_string('close').'></a>';
}

WITHIN THIS: /*display the theme logo by checking if the default logo was overwritten in the backend. * the function is located at framework/php/function-set-avia-frontend-functions.php in case you need to edit the output*/
FOR THIS LINE OF CODE:
$output .= avia_logo(AVIA_BASE_URL.'images/layout/logo.png', $addition, 'span', true);
I HAVE THIS CODE:
$output .= avia_logo(AVIA_BASE_URL.'images/layout/logo.png', $addition, '<strong>strong</strong>', true);

WITHIN THIS CODE: /*display the main navigation menu * modify the output in your wordpress admin backend at appearance->menus */
JUST BEFORE THIS LINE OF CODE:
$main_nav = "<nav class='main_menu' data-selectname='".__('Select a page','avia_framework')."' ".avia_markup_helper(array('context' => 'nav', 'echo' => false)).">";
I HAVE THIS CODE:

/*Conditionally replaced code for the UberMenu manual integration */					
if( function_exists( 'ubermenu' ) ){
    $output.= ubermenu( 'main' , array( 'theme_location' => 'avia' , 'echo' => false ) ); 
}
else{
    $output .= "<nav class='main_menu' data-selectname='".__('Select a page','avia_framework')."' ".avia_markup_helper(array('context' => 'nav', 'echo' => false)).">";

I have added the CSS code you suggested in the general styling and the hamburger menu did not work. So I modified the CSS so the hamburger menu does not display at all. That worked. Once I checked on my ihpone, I see the hamburger menu but also see it duplicated at the end of the menu list as an item. Here’s a screenshot:
https://www.dropbox.com/s/mt99dyi7mstrq0l/hamburger%20menu.jpg?dl=0

Also any help with with the code should be in the php file would be greatly appreciated.

Thanks
Lyse