Fatal Errors still with 5.2.1

Hi there,

after updating to 5.2.0 some sites were facing issues with fatal errors, so i really appreciate the quick release of 5.2.1 to fix these issues.

One Website though ist still facing issues after the update to 5.2.1 in combination with the Membership Plugin “Digimember”.

On creating a new Order, a new user account should be created, too. Instead there occurs a fatal error. Here’s the debug log:

Ein Fehler vom Typ E_ERROR wurde in der Zeile 817 der Datei /wp-content/plugins/all-in-one-wp-security-and-firewall/classes/wp-security-utility.php verursacht. Fehlermeldung: Uncaught TypeError: get_class(): Argument #1 ($object) must be of type object, null given in /wp-content/plugins/all-in-one-wp-security-and-firewall/classes/wp-security-utility.php:817
Stack trace:
#0 /wp-content/plugins/all-in-one-wp-security-and-firewall/classes/wp-security-audit-event-handler.php(57): AIOWPSecurity_Utility::normalise_call_stack_args(Array)
#1 /wp-includes/class-wp-hook.php(308): AIOWPSecurity_Audit_Event_Handler->record_event('user_registrati...', Array, 'info')
#2 /wp-includes/class-wp-hook.php(332): WP_Hook->apply_filters('', Array)
#3 /wp-includes/plugin.php(517): WP_Hook->do_action(Array)
#4 /wp-content/plugins/all-in-one-wp-security-and-firewall/classes/wp-security-audit-events.php(443): do_action('aiowps_record_e...', 'user_registrati...', Array, 'info')
#5 /wp-content/plugins/all-in-one-wp-security-and-firewall/classes/wp-security-user-registration.php(44): AIOWPSecurity_Audit_Events::event_user_registration(8218, 'admin')
#6 /wp-includes/class-wp-hook.php(310): AIOWPSecurity_User_Registration->aiowps_user_registration_action_handler(8218)
#7 /wp-includes/class-wp-hook.php(332): WP_Hook->apply_filters(false, Array)
#8 /wp-includes/plugin.php(517): WP_Hook->do_action(Array)
#9 /wp-includes/user.php(2494): do_action('user_register', 8218, Array)
#10 /wp-includes/user.php(2762): wp_insert_user(Array)
#11 /wp-content/plugins/digimember/application/library/payment_handler/payment_handler.php(767): wp_create_user('xxx@xxx....', 'bHbUv5Hy', 'xxx@xxx....')
#12 /wp-content/plugins/digimember/application/library/payment_handler/payment_handler.php(1107): digimember_PaymentHandlerLib->getUserId('xxx@xxx....', Array, false, '')
#13 /wp-content/plugins/digimember/application/library/payment_handler/payment_handler.php(559): digimember_PaymentHandlerLib->_handleMembershipProduct('manual', 0, 'ACF 22.07.-23.0...', 'xxx@xxx....', Object(stdClass), 1, Array, true, '', '', '', 'none', '', '', Array, 'none')
#14 /wp-content/plugins/digimember/application/library/payment_handler/payment_handler.php(107): digimember_PaymentHandlerLib->onSale('manual', 0, 'ACF 22.07.-23.0...', 'xxx@xxx....', Array, Array, true, '')
#15 /wp-content/plugins/digimember/application/controller/admin/order_edit.php(311): digimember_PaymentHandlerLib->manuallyCreateSale('xxx@xxx....', 'Fa###', 'Na#######', 'ACF 22.07.-23.0...', '27')
#16 /wp-content/plugins/digimember/system/controller/admin/form.php(52): digimember_AdminOrderEditController->setData('new', Array)
#17 /wp-content/plugins/digimember/system/base/controller.php(36): ncore_AdminFormController->handleRequest()
#18 /wp-content/plugins/digimember/system/core/init.php(609): ncore_Controller->dispatch()
#19 /wp-includes/class-wp-hook.php(308): ncore_InitCore->cbLoadAdminController('')
#20 /wp-includes/class-wp-hook.php(332): WP_Hook->apply_filters('', Array)
#21 /wp-includes/plugin.php(517): WP_Hook->do_action(Array)
#22 /wp-admin/admin.php(259): do_action('digimember_page...')
#23 {main}
 thrown

(Please note that i hashed the containing user information. )

Rolling back to 5.1.9 helped, but maybe you can solve this one too, so i can do the next update.