Update enfold theme

Hi,
I got this error on my website when I want to update enfold to the latest version.
My hosting provider they say it is because of the php version in Enfold?
I can not access my website by wordpress after I got the error
Below is the message I got from WordPress – what can do?

Error on my website
Warning: Creating default object from empty value in /customers/6/8/9/lejauto.nu/httpd.www/wp-content/themes/enfold/config-templatebuilder/avia-shortcodes/slideshow_layerslider/slideshow_layerslider.php on line 28 Warning: Cannot modify header information – headers already sent by (output started at /customers/6/8/9/lejauto.nu/httpd.www/wp-content/themes/enfold/config-templatebuilder/avia-shortcodes/slideshow_layerslider/slideshow_layerslider.php:28) in /customers/6/8/9/lejauto.nu/httpd.www/wp-content/plugins/onecom-vcache/vcaching.php on line 549 Warning: Cannot modify header information – headers already sent by (output started at /customers/6/8/9/lejauto.nu/httpd.www/wp-content/themes/enfold/config-templatebuilder/avia-shortcodes/slideshow_layerslider/slideshow_layerslider.php:28) in /customers/6/8/9/lejauto.nu/httpd.www/wp-content/plugins/onecom-vcache/vcaching.php on line 557 Warning: Cannot modify header information – headers already sent by (output started at /customers/6/8/9/lejauto.nu/httpd.www/wp-content/themes/enfold/config-templatebuilder/avia-shortcodes/slideshow_layerslider/slideshow_layerslider.php:28) in /customers/6/8/9/lejauto.nu/httpd.www/wp-content/plugins/onecom-vcache/vcaching.php on line 186