Fatal Error when updating theme version

I am running an older version 5.4.1.

When updating to 5.6.10 I get the error below:
Fatal error: Uncaught Error: Class “aviaBuilder\base\aviaElementStylingResponsive” not found in /sitepath/wp-content/themes/enfold/config-templatebuilder/avia-template-builder/php/class-element-styling.php:14 Stack trace: #0 /sitepath/wp-content/themes/enfold/config-templatebuilder/avia-template-builder/php/class-template-builder.php(682): require_once() #1 /sitepath/wp-includes/class-wp-hook.php(324): AviaBuilder->loadLibraries(”) #2 /sitepath/wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters(NULL, Array) #3 /sitepath/wp-includes/plugin.php(517): WP_Hook->do_action(Array) #4 /sitepath/wp-settings.php(643): do_action(‘init’) #5 /sitepath/wp-config.php(103): require_once(‘/www/sitepath…’) #6 /sitepath/wp-load.php(50): require_once(‘/www/sitepath…’) #7 /sitepath/wp-admin/admin.php(34): require_once(‘/www/sitepath…’) #8 /sitepath/wp-admin/plugins.php(10): require_once(‘/www/sitepath…’) #9 {main} thrown in /sitepath/wp-content/themes/enfold/config-templatebuilder/avia-template-builder/php/class-element-styling.php on line 14

Any idea what I am doing wrong?