Error when trying to go appearance > customise in WP admin cp

Hi – I don’t know if this is themes-related but I got an email from my WP after failing to go to the appearance -> customise menu

When seeking help with this issue, you may be asked for some of the following information:
WordPress version 5.5
Current theme: Enfold (version 4.7.3)
Current plugin:  (version )
PHP version 7.2.32

Error Details
=============
An error of type E_ERROR was caused in line 563 of the file /home/dandelion/public_html/wp-content/themes/enfold/config-gutenberg/class-avia-gutenberg.php. Error message: Uncaught Error: Call to undefined function gutenberg_can_edit_post_type() in /home/dandelion/public_html/wp-content/themes/enfold/config-gutenberg/class-avia-gutenberg.php:563
Stack trace:
#0 /home/dandelion/public_html/wp-content/themes/enfold/config-gutenberg/class-avia-gutenberg.php(423): Avia_Gutenberg->can_use_block_editor('post', true)
#1 /home/dandelion/public_html/wp-content/themes/enfold/config-gutenberg/class-avia-gutenberg.php(458): Avia_Gutenberg->init_force_classic_post_types()
#2 /home/dandelion/public_html/wp-content/themes/enfold/config-gutenberg/class-avia-gutenberg.php(533): Avia_Gutenberg->get_force_classic_post_types()
#3 /home/dandelion/public_html/wp-content/themes/enfold/config-gutenberg/class-avia-gutenberg.php(661): Avia_Gutenberg->force_classic_editor('page')
#4 /home/dandelion/public_html/wp-includes/class-wp-hook.php(287): Avia_Gutenberg->handler_display_post_states(Array, Object(WP_Post))
#5 /home/dandelion/public_html/wp-includes/plugin.php(206): WP_Hook->apply_filters(Array, Arr

I am also surprised that I am not offered the opportunity to update to 4.7.6.2. No idea why that might be – I purchased the theme.

Is this a familiar problem – I couldn’t find an exact equivalent using a forum search.