Mailing List Subscription

Notice: Undefined index: HTTP_REFERER in CRM_Core_Controller->setDestination() (line 828 of /var/www/gsvlive/vendor/civicrm/civicrm-core/CRM/Core/Controller.php).

CRM_Core_Controller->setDestination(NULL, 1) (Line: 29)
CRM_Mailing_Form_Subscribe->preProcess() (Line: 673)
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: 355)
CRM_Core_Controller->run() (Line: 98)
CRM_Utils_Wrapper->run('CRM_Mailing_Form_Subscribe', 'Subscribe', Array) (Line: 292)
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: 580)
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: 169)
Symfony\Component\HttpKernel\HttpKernel->handleRaw(Object, 1) (Line: 81)
Symfony\Component\HttpKernel\HttpKernel->handle(Object, 1, 1) (Line: 58)
Drupal\Core\StackMiddleware\Session->handle(Object, 1, 1) (Line: 48)
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: 49)
Asm89\Stack\Cors->handle(Object, 1, 1) (Line: 48)
Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle(Object, 1, 1) (Line: 51)
Drupal\Core\StackMiddleware\NegotiationMiddleware->handle(Object, 1, 1) (Line: 23)
Stack\StackedHttpKernel->handle(Object, 1, 1) (Line: 718)
Drupal\Core\DrupalKernel->handle(Object) (Line: 19)

Error message