Yes I’m sure.
I inserted
debug_print_backtrace(); die();
in acf-value-functions.php on line 351 and the stacktrace showed me exactly the call in the acf/init action.
#0 acf_log_invalid_field_notice(Array ([ID] => 0,[key] => ,[label] => ,[name] => theme_mapbox_access_token,[prefix] => ,[type] => ,[value] => ,[menu_order] => 0,[instructions] => ,[required] => ,[id] => ,[class] => ,[conditional_logic] => ,[parent] => 0,[wrapper] => Array ([width] => ,[class] => ,[id] => ),[_name] => theme_mapbox_access_token,[_valid] => 1), acf_get_value) called at [/var/www/clients/client1/web4/web/wp-includes/class-wp-hook.php:303]
#1 WP_Hook->apply_filters(, Array ([0] => Array ([ID] => 0,[key] => ,[label] => ,[name] => theme_mapbox_access_token,[prefix] => ,[type] => ,[value] => ,[menu_order] => 0,[instructions] => ,[required] => ,[id] => ,[class] => ,[conditional_logic] => ,[parent] => 0,[wrapper] => Array ([width] => ,[class] => ,[id] => ),[_name] => theme_mapbox_access_token,[_valid] => 1),[1] => acf_get_value)) called at [/var/www/clients/client1/web4/web/wp-includes/class-wp-hook.php:327]
#2 WP_Hook->do_action(Array ([0] => Array ([ID] => 0,[key] => ,[label] => ,[name] => theme_mapbox_access_token,[prefix] => ,[type] => ,[value] => ,[menu_order] => 0,[instructions] => ,[required] => ,[id] => ,[class] => ,[conditional_logic] => ,[parent] => 0,[wrapper] => Array ([width] => ,[class] => ,[id] => ),[_name] => theme_mapbox_access_token,[_valid] => 1),[1] => acf_get_value)) called at [/var/www/clients/client1/web4/web/wp-includes/plugin.php:470]
#3 do_action(acf/get_invalid_field_value, Array ([ID] => 0,[key] => ,[label] => ,[name] => theme_mapbox_access_token,[prefix] => ,[type] => ,[value] => ,[menu_order] => 0,[instructions] => ,[required] => ,[id] => ,[class] => ,[conditional_logic] => ,[parent] => 0,[wrapper] => Array ([width] => ,[class] => ,[id] => ),[_name] => theme_mapbox_access_token,[_valid] => 1), acf_get_value) called at [/var/www/clients/client1/web4/web/wp-content/themes/pixelcube/lib/advanced-custom-fields-pro/includes/acf-value-functions.php:72]
#4 acf_get_value(options, Array ([ID] => 0,[key] => ,[label] => ,[name] => theme_mapbox_access_token,[prefix] => ,[type] => ,[value] => ,[menu_order] => 0,[instructions] => ,[required] => ,[id] => ,[class] => ,[conditional_logic] => ,[parent] => 0,[wrapper] => Array ([width] => ,[class] => ,[id] => ),[_name] => theme_mapbox_access_token,[_valid] => 1)) called at [/var/www/clients/client1/web4/web/wp-content/themes/pixelcube/lib/advanced-custom-fields-pro/includes/api/api-template.php:45]
#5 get_field(theme_mapbox_access_token, options) called at [/var/www/clients/client1/web4/web/wp-content/themes/pixelcube/functions/mapbox/class-customtheme-mapbox.php:17]
#6 Customtheme_Mapbox::{closure}(5) called at [/var/www/clients/client1/web4/web/wp-includes/class-wp-hook.php:303]
#7 WP_Hook->apply_filters(, Array ([0] => 5)) called at [/var/www/clients/client1/web4/web/wp-includes/class-wp-hook.php:327]
#8 WP_Hook->do_action(Array ([0] => 5)) called at [/var/www/clients/client1/web4/web/wp-includes/plugin.php:470]
#9 do_action(acf/init, 5) called at [/var/www/clients/client1/web4/web/wp-content/themes/pixelcube/lib/advanced-custom-fields-pro/acf.php:332]
#10 ACF->init() called at [/var/www/clients/client1/web4/web/wp-content/themes/pixelcube/lib/advanced-custom-fields-pro/includes/api/api-helpers.php:226]
#11 acf_init() called at [/var/www/clients/client1/web4/web/wp-content/themes/pixelcube/lib/advanced-custom-fields-pro/includes/api/api-template.php:144]
#12 acf_maybe_get_field(theme_header_nav_type, options) called at [/var/www/clients/client1/web4/web/wp-content/themes/pixelcube/lib/advanced-custom-fields-pro/includes/api/api-template.php:26]
#13 get_field(theme_header_nav_type, options) called at [/var/www/clients/client1/web4/web/wp-content/themes/pixelcube/class-customtheme.php:127]
#14 Customtheme::load_header_nav() called at [/var/www/clients/client1/web4/web/wp-content/themes/pixelcube/functions.php:65]
#15 include(/var/www/clients/client1/web4/web/wp-content/themes/pixelcube/functions.php) called at [/var/www/clients/client1/web4/web/wp-settings.php:546]
#16 require_once(/var/www/clients/client1/web4/web/wp-settings.php) called at [/var/www/clients/client1/web4/web/wp-config.php:131]
#17 require_once(/var/www/clients/client1/web4/web/wp-config.php) called at [/var/www/clients/client1/web4/web/wp-load.php:50]
#18 require_once(/var/www/clients/client1/web4/web/wp-load.php) called at [/var/www/clients/client1/web4/web/wp-blog-header.php:13]
#19 require(/var/www/clients/client1/web4/web/wp-blog-header.php) called at [/var/www/clients/client1/web4/web/index.php:17]
