Conflict with theme and WP 5.4 when viewing APPEARANCE > CUSTOMIZE

Hey guys,
when I go to APPEARANCE > CUSTOMIZE … I receive this:

7 PHP Fatal error: Uncaught Error: Call to undefined function gutenberg_can_edit_post_type() in /nas/content/live/burnbrightprod/wp-content/themes/enfold/config-gutenberg/class-avia-gutenberg.php:563\nStack trace:\n#0 /nas/content/live/burnbrightprod/wp-content/themes/enfold/config-gutenberg/class-avia-gutenberg.php(423): Avia_Gutenberg->can_use_block_editor(‘post’, true)\n#1 /nas/content/live/burnbrightprod/wp-content/themes/enfold/config-gutenberg/class-avia-gutenberg.php(458): Avia_Gutenberg->init_force_classic_post_types()\n#2 /nas/content/live/burnbrightprod/wp-content/themes/enfold/config-gutenberg/class-avia-gutenberg.php(533): Avia_Gutenberg->get_force_classic_post_types()\n#3 /nas/content/live/burnbrightprod/wp-content/themes/enfold/config-gutenberg/class-avia-gutenberg.php(661): Avia_Gutenberg->force_classic_editor(‘page’)\n#4 /nas/content/live/burnbrightprod/wp-includes/class-wp-hook.php(287): Avia_Gutenberg->handler_display_post_states(Array, Object(WP_Post))\n#5 /nas/content/live/burnbrightprod/wp-includes/plugin.php(206) in /nas/content/live/burnbrightprod/wp-content/themes/enfold/config-gutenberg/class-avia-gutenberg.php on line 563

I know the ideal way is to set up the child-theme.
But that has not been working either. The theme won’t inherit anything from the parent theme.
So really, I have 2 challenges here.

https://www.burnrightproducts.com/

Thanks