Received critical error on older Enfold site

I have a site from a few years ago that has been running smoothly on Enfold 3.2.3. I am afraid upgrading will damage the site, but just today I received a critical error resulting in no content on the page: http://ksha.com/

Any ideas on how I could fix this issue?

An error of type E_ERROR was caused in line 222 of the file /home/ksha/public_html/new/wp-content/themes/enfold/framework/php/class-htmlhelper.php. Error message: Uncaught Error: Function name must be a string in /home/ksha/public_html/new/wp-content/themes/enfold/framework/php/class-htmlhelper.php:222
Stack trace:
#0 /home/ksha/public_html/new/wp-content/themes/enfold/framework/php/class-htmlhelper.php(131): avia_htmlhelper->render_single_element(Array)
#1 /home/ksha/public_html/new/wp-content/themes/enfold/framework/php/class-adminpages.php(205): avia_htmlhelper->create_container_based_on_slug(Array, 'avia_active_con...')
#2 /home/ksha/public_html/new/wp-includes/class-wp-hook.php(292): avia_adminpages->render_page('')
#3 /home/ksha/public_html/new/wp-includes/class-wp-hook.php(316): WP_Hook->apply_filters('', Array)
#4 /home/ksha/public_html/new/wp-includes/plugin.php(484): WP_Hook->do_action(Array)
#5 /home/ksha/public_html/new/wp-admin/admin.php(259): do_action('toplevel_page_a...')
#6 {main}
  thrown