シロハチ様、ご回答ありがとうございます。
上記を試したのですが、デバックで

in CustomerStatus.php line 52

at AnnotationDriver->getAllClassNames()
in MappingDriverChain.php line 103

at MappingDriverChain->getAllClassNames()
in ClassMetadataFactory.php line 351

at ClassMetadataFactory->addDefaultDiscriminatorMap(object(ClassMetadata))
in ClassMetadataFactory.php line 237

at ClassMetadataFactory->doLoadMetadata(object(ClassMetadata), object(ClassMetadata), false, array())
in AbstractClassMetadataFactory.php line 304

at AbstractClassMetadataFactory->loadMetadata('Plugin\\SalesRestrictions4\\Entity\\ProductCustomerRank')
in ClassMetadataFactory.php line 78

at ClassMetadataFactory->loadMetadata('Plugin\\SalesRestrictions4\\Entity\\ProductCustomerRank')
in AbstractClassMetadataFactory.php line 183

at AbstractClassMetadataFactory->getMetadataFor('Plugin\\SalesRestrictions4\\Entity\\ProductCustomerRank')
in EntityManager.php line 283

at EntityManager->getClassMetadata('Plugin\\SalesRestrictions4\\Entity\\ProductCustomerRank')
in EntityManager_9a5be93.php line 110

at EntityManager_9a5be93->getClassMetadata('Plugin\\SalesRestrictions4\\Entity\\ProductCustomerRank')
in ServiceEntityRepository.php line 39

at ServiceEntityRepository->__construct(object(Registry), 'Plugin\\SalesRestrictions4\\Entity\\ProductCustomerRank')
in ProductCustomerRankRepository.php line 21

at ProductCustomerRankRepository->__construct(object(Registry))
in EccubeDevDebugProjectContainer.php line 3430

at EccubeDevDebugProjectContainer->getProductCustomerRankRepositoryService()
in EccubeDevDebugProjectContainer.php line 3088

at EccubeDevDebugProjectContainer->getQueriesService()
in EccubeDevDebugProjectContainer.php line 3300

at EccubeDevDebugProjectContainer->getProductRepositoryService()
in EccubeDevDebugProjectContainer.php line 3380

at EccubeDevDebugProjectContainer->getEccubeExtensionService()
in EccubeDevDebugProjectContainer.php line 3028

at EccubeDevDebugProjectContainer->getTwigService()
in EccubeDevDebugProjectContainer.php line 3130

at EccubeDevDebugProjectContainer->getMobileTemplatePathListenerService()
in EccubeDevDebugProjectContainer.php line 3703

at EccubeDevDebugProjectContainer->ContainerYrgkrya\{closure}()
in EventDispatcher.php line 229

at EventDispatcher->sortListeners('kernel.request')
in EventDispatcher.php line 61

at EventDispatcher->getListeners('kernel.request')
in ContainerAwareEventDispatcher.php line 128

at ContainerAwareEventDispatcher->getListeners('kernel.request')
in TraceableEventDispatcher.php line 262

at TraceableEventDispatcher->preProcess('kernel.request')
in TraceableEventDispatcher.php line 137

at TraceableEventDispatcher->dispatch('kernel.request', object(GetResponseEvent))
in HttpKernel.php line 127

at HttpKernel->handleRaw(object(Request), 1)
in HttpKernel.php line 68

at HttpKernel->handle(object(Request), 1, true)
in Kernel.php line 200

at Kernel->handle(object(Request))
in index.php line 76
と出てきます。
何か、解決方法がお分かりになるようでしたら、ご回答をよろしくお願いいたします。