PHP Fatal error: Uncaught Error: Undefined constant

According to GPT-5 (not that I trust it, so hence asking you, the author):

The fatal happens because the autoloader runs before GENESIS_AUTHOR_PRO_CLASSES_DIR is defined.

In your file:

• gapro_autoloader uses GENESIS_AUTHOR_PRO_CLASSES_DIR
• spl_autoload_register is called
• Only after that, the define statements are declared

So on the first autoload attempt, the constant is undefined and PHP fatals.

Fix: move the define block above the autoloader registration (and any code that uses those constants).

Thanks.
It mostly just gets me that notification from the host and the site is indeed up.

Today, when I tried to post a new Book, I got:
“”Critical Error”There has been a critical error on this website. Please check your site admin email inbox for instructions. If you continue to have problems, please try the support forums.”

The funny thing is that it posted the Book, even with the error. But I get the error every time I try to update it.

This is the error log today:

PHP Fatal error: Uncaught Error: Undefined constant “GENESIS_AUTHOR_PRO_CLASSES_DIR” in /nas/content/live/MYSITENAME/wp-content/plugins/genesis-author-pro/plugin.php:55#012Stack trace:#012#0 /nas/content/live/MYSITENAME/wp-includes/plugin.php(130): gapro_autoloader(‘Genesis_Author_…’)#012#1 /nas/content/live/MYSITENAME/wp-includes/plugin.php(442): add_filter(‘activate_genesi…’, Array, 10, 1)#012#2 /nas/content/live/MYSITENAME/wp-includes/plugin.php(871): add_action(‘activate_genesi…’, Array)#012#3 /nas/content/live/MYSITENAME/wp-content/plugins/genesis-author-pro/plugin.php(61): register_activation_hook(‘genesis-author-…’, Array)#012#4 /nas/content/live/MYSITENAME/wp-settings.php(545): include_once(‘/nas/content/li…’)#012#5 /nas/content/live/MYSITENAME/wp-config.php(119): require_once(‘/nas/content/li…’)#012#6 /nas/content/live/MYSITENAME/wp-load.php(50): require_once(‘/nas/content/li…’)#012#7 /nas/content/live/MYSITENAME/wp-admin/admin.php(35): require_once(‘/nas/content/li…’)#012#8 {main}#012 thrown in /nas/content/live/MYSITENAME/wp-content/plugins/genesis-author-pro/plugin.php on line 55

Below is what the email error says today.

Would it be helpful to know what other plugins we are running?

When seeking help with this issue, you may be asked for some of the following information:
WordPress version 6.8.3
Active theme: Author Pro Theme (version 1.0.0)
Current plugin: Osom Author Pro (version 2.0)
PHP version 8.4.14

Error Details

An error of type E_ERROR was caused in line 55 of the file /nas/content/live/MYSITENAME/wp-content/plugins/genesis-author-pro/plugin.php. Error message: Uncaught Error: Undefined constant “GENESIS_AUTHOR_PRO_CLASSES_DIR” in /nas/content/live/MYSITENAME/wp-content/plugins/genesis-author-pro/plugin.php:55
Stack trace: 0 /nas/content/live/MYSITENAME/wp-includes/plugin.php(130): gapro_autoloader(‘Genesis_Author_…’) 1 /nas/content/live/MYSITENAME/wp-includes/plugin.php(442): add_filter(‘activate_genesi…’, Array, 10, 1) 2 /nas/content/live/MYSITENAME/wp-includes/plugin.php(871): add_action(‘activate_genesi…’, Array) 3 /nas/content/live/MYSITENAME/wp-content/plugins/genesis-author-pro/plugin.php(61): register_activation_hook(‘genesis-author-…’, Array) 4 /nas/content/live/MYSITENAME/wp-settings.php(545): include_once(‘/nas/content/li…’) 5 /nas/content/live/MYSITENAME/wp-config.php(119): require_once(‘/nas/content/li…’) 6 /nas/content/live/MYSITENAME/wp-load.php(50): require_once(‘/nas/content/li…’) 7 /nas/content/live/MYSITENAME/wp-login.php(12): require(‘/nas/content/li…’) 8 {main}

thrown

Thank you. Really appreciate you helping troubleshoot

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