Error: Cannot access protected property Drupal\bat_event\Entity\EventType::$target_entity_type in Drupal\bat_api\Plugin\ServiceDefinition\UnitIndex->processRequest() (line 113 of /var/www/html/myDev/web/modules/contrib/bat_api/src/Plugin/ServiceDefinition

hi.. i have an error isue on dev, what this mean;
Error: Cannot access protected property Drupal\bat_event\Entity\EventType::$target_entity_type in Drupal\bat_api\Plugin\ServiceDefinition\UnitIndex->processRequest() (line 113 of /var/www/html/myDev/web/modules/contrib/bat_api/src/Plugin/ServiceDefinition/UnitIndex.php)

#0 /var/www/html/myDev/web/modules/contrib/services/src/Controller/Services.php(68): Drupal\bat_api\Plugin\ServiceDefinition\UnitIndex->processRequest(Object(Symfony\Component\HttpFoundation\Request), Object(Drupal\Core\Routing\RouteMatch), Object(Symfony\Component\Serializer\Serializer))
#1 [internal function]: Drupal\services\Controller\Services->processRequest(Object(Symfony\Component\HttpFoundation\Request), Object(Drupal\Core\Routing\RouteMatch), 'bat_api', 'unit_index:cale...')
#2 /var/www/html/myDev/web/core/lib/Drupal/Core/EventSubscriber/EarlyRenderingControllerWrapperSubscriber.php(123): call_user_func_array(Array, Array)
#3 /var/www/html/myDev/web/core/lib/Drupal/Core/Render/Renderer.php(573): Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}()
#4 /var/www/html/myDev/web/core/lib/Drupal/Core/EventSubscriber/EarlyRenderingControllerWrapperSubscriber.php(124): Drupal\Core\Render\Renderer->executeInRenderContext(Object(Drupal\Core\Render\RenderContext), Object(Closure))
#5 /var/www/html/myDev/web/core/lib/Drupal/Core/EventSubscriber/EarlyRenderingControllerWrapperSubscriber.php(97): Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->wrapControllerExecutionInRenderContext(Array, Array)
#6 /var/www/html/myDev/vendor/symfony/http-kernel/HttpKernel.php(151): Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}()
#7 /var/www/html/myDev/vendor/symfony/http-kernel/HttpKernel.php(68): Symfony\Component\HttpKernel\HttpKernel->handleRaw(Object(Symfony\Component\HttpFoundation\Request), 1)