Warning: Creating default object from empty value in /home/customer/www/

Hello! i’m having problems with an enfold site. I read this threat > https://kriesi.at/support/topic/layer-slider-warning-and-admins-unable-to-login-to-website/ but still can’t find the solution. I upgraded enfold to the latest realease, and now when i’m logged in, the site is rendered fine, but when i’m not logged in, the site now appears but with a lot of css issues (icons not showing), entire sections missing, layerslider not showing background video, etc…

I disabled css compression as someone suggest in the mentioned threat but the error is still there…
In the top of the page, this message appears (only when i’m logged out):

Warning: Creating default object from empty value in /home/customer/www/likid.cl/public_html/wp-content/themes/enfold/config-templatebuilder/avia-shortcodes/slideshow_layerslider/slideshow_layerslider.php on line 28

Please let me know what it can be, my client is a little nervous about this. Thanks!