theme caused a fatal error on my site

Please Help! I bought Envato in 2016 but now my log in does not work, However the main problem is I was working on my Serene-Vista.com site using my wordpress admin and the site pages started to not load. then I got this email from word press:

Howdy!

Since WordPress 5.2 there is a built-in feature that detects when a plugin or theme causes a fatal error on your site, and notifies you with this automated email.

In this case, WordPress caught an error with your theme, Enfold.

First, visit your website (https://www.serene-vista.com/) and check for any visible issues. Next, visit the page where the error was caught (https://www.serene-vista.com/wp-admin/post.php?post=183&action=edit&message=1) and check for any visible issues.

Please contact your host for assistance with investigating this issue further.

If your site appears broken and you can’t access your dashboard normally, WordPress now has a special “recovery mode”. This lets you safely login to your dashboard and investigate further.

When seeking help with this issue, you may be asked for some of the following information:
WordPress version 5.3.2
Current theme: Enfold (version 3.8)
Current plugin: (version )
PHP version 7.2.24
Error Details
=============
An error of type E_ERROR was caused in line 489 of the file /home/danchrist/serene-vista.com/wp-content/themes/enfold/config-templatebuilder/avia-template-builder/php/shortcode-template.class.php. Error message: Uncaught Error: Cannot use string offset as an array in /home/danchrist/serene-vista.com/wp-content/themes/enfold/config-templatebuilder/avia-template-builder/php/shortcode-template.class.php:489
Stack trace:
#0 /home/danchrist/serene-vista.com/wp-content/themes/enfold/config-templatebuilder/avia-template-builder/php/shortcode-template.class.php(443): aviaShortcodeTemplate->create_sortable_editor_element(Array)
#1 /home/danchrist/serene-vista.com/wp-content/themes/enfold/config-templatebuilder/avia-template-builder/php/template-builder.class.php(397): aviaShortcodeTemplate->prepare_editor_element()
#2 /home/danchrist/serene-vista.com/wp-includes/class-wp-hook.php(288): AviaBuilder->js_template_editor_elements(”)
#3 /home/danchrist/serene-vista.com/wp-includes/class-wp-hook.php(312): WP_Hook->apply_filters(”, Array)
#4 /home/danchrist/serene-vista.com/wp-includes/plugin.php(478): WP_Hook->do_action(Array)
#5 /home/danchrist/serene-vista.com/wp-includes/media-template.php(1455): do_action(‘print_media_tem…’