I am having similar issue, how do we resolve this. I tried Specular 4.1.4 and 4.0.9, both have this issue.
WordPress version 5.7.2
Current plugin: Specular WPBakery Addons & Backward Compatibility (version 1.0.0) PHP version 7.3.12
Error Details
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An error of type E_ERROR was caused in line 220 of the file /var/www/wp-content/plugins/specular-wpbakery-addons/includes/wpbakery-config.php. Error message: Uncaught Error: Call to undefined function codeless_get_image_sizes() in /var/www/wp-content/plugins/specular-wpbakery-addons/includes/wpbakery-config.php:220
Stack trace:
#0 /var/www/wp-content/plugins/specular-wpbakery-addons/public/class-specular-wpbakery-addons-public.php(114): require_once()
#1 /var/www/wp-includes/class-wp-hook.php(292): Specular_Wpbakery_Addons_Public->load_elements(”)
#2 /var/www/wp-includes/class-wp-hook.php(316): WP_Hook->apply_filters(NULL, Array)
#3 /var/www/wp-includes/plugin.php(484): WP_Hook->do_action(Array)
#4 /var/www/wp-settings.php(560): do_action(‘init’)
#5 /var/www/wp-config.php(101): require_once(‘/var/www/wp-set…’)
#6 /var/www/wp-load.php(37): require_once(‘/var/www/wp-con…’)
#7 /var/www/wp-admin/admin.php(34): require_once(‘/var/www/wp-loa…’)
#8 /var/www/wp-admin/plugins.php(10): require_once(‘/var/www/wp-adm…’)
#9 {main}
thrown