Error message
Notice: Undefined index: HTTP_REFERER in CRM_Core_Controller->setDestination() (line 801 of /var/www/prolydian/vendor/civicrm/civicrm-core/CRM/Core/Controller.php).CRM_Core_Controller->setDestination(NULL, 1) (Line: 29)
CRM_Mailing_Form_Subscribe->preProcess() (Line: 621)
CRM_Core_Form->buildForm() (Line: 76)
CRM_Core_QuickForm_Action_Display->perform(Object, 'display') (Line: 203)
HTML_QuickForm_Controller->handle(Object, 'display') (Line: 103)
HTML_QuickForm_Page->handle('display') (Line: 352)
CRM_Core_Controller->run() (Line: 98)
CRM_Utils_Wrapper->run('CRM_Mailing_Form_Subscribe', 'Subscribe', Array) (Line: 286)
CRM_Core_Invoke::runItem(Array) (Line: 69)
CRM_Core_Invoke::_invoke(Array) (Line: 36)
CRM_Core_Invoke::invoke(Array) (Line: 88)
Drupal\civicrm\Civicrm->invoke(Array) (Line: 80)
Drupal\civicrm\Controller\CivicrmController->main(Array, '')
call_user_func_array(Array, Array) (Line: 123)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}() (Line: 573)
Drupal\Core\Render\Renderer->executeInRenderContext(Object, Object) (Line: 124)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->wrapControllerExecutionInRenderContext(Array, Array) (Line: 97)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}() (Line: 151)
Symfony\Component\HttpKernel\HttpKernel->handleRaw(Object, 1) (Line: 68)
Symfony\Component\HttpKernel\HttpKernel->handle(Object, 1, 1) (Line: 57)
Drupal\Core\StackMiddleware\Session->handle(Object, 1, 1) (Line: 47)
Drupal\Core\StackMiddleware\KernelPreHandle->handle(Object, 1, 1) (Line: 191)
Drupal\page_cache\StackMiddleware\PageCache->fetch(Object, 1, 1) (Line: 128)
Drupal\page_cache\StackMiddleware\PageCache->lookup(Object, 1, 1) (Line: 82)
Drupal\page_cache\StackMiddleware\PageCache->handle(Object, 1, 1) (Line: 47)
Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle(Object, 1, 1) (Line: 52)
Drupal\Core\StackMiddleware\NegotiationMiddleware->handle(Object, 1, 1) (Line: 23)
Stack\StackedHttpKernel->handle(Object, 1, 1) (Line: 708)
Drupal\Core\DrupalKernel->handle(Object) (Line: 19)