TypeError: Argument 1 passed to Drupal\wow_tours\WowTours::calculatePrice() must implement interface Drupal\Core\Entity\EntityInterface, null given, called in /var/www/zovnish/data/www/zovnish.com/modules/glyanec/zovnish/src/Form/TourBooking.php on line 1435 in Drupal\wow_tours\WowTours->calculatePrice() (line 710 of /var/www/zovnish/data/www/zovnish.com/modules/glyanec/wow_tours/src/WowTours.php).

Drupal\wow_tours\WowTours->calculatePrice(NULL, 0, 'price', NULL, NULL, 0, NULL) (Line: 1435)
Drupal\zovnish\Form\TourBooking->calcPrice(Object) (Line: 191)
Drupal\zovnish\Form\TourBooking->buildForm(Array, Object)
call_user_func_array(Array, Array) (Line: 532)
Drupal\Core\Form\FormBuilder->retrieveForm('tour_booking_form', Object) (Line: 278)
Drupal\Core\Form\FormBuilder->buildForm(Object, Object) (Line: 219)
Drupal\Core\Form\FormBuilder->getForm(Object) (Line: 473)
Drupal\zovnish\Controller\Pages\TourBooking::page('584', )
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: 709)
Drupal\Core\DrupalKernel->handle(Object) (Line: 19)