UniqueAttributesInterceptor Exception during guest checkout in CX2011

[former_member715462]

de.hybris.platform.servicelayer.exceptions.ModelSavingException: [de.hybris.platform.servicelayer.interceptor.impl.UniqueAttributesInterceptor@138173a9]:Unklare eindeutige Schlüsse: {uid=test@test.com} für Modell CustomerModel (<unsaved>) - 1 Produkte mit denselben Schlüsseln gefunden
	at de.hybris.platform.servicelayer.internal.model.impl.wrapper.ModelWrapper.invokeValidateInterceptors(ModelWrapper.java:300) ~[coreserver.jar:?]
	at de.hybris.platform.servicelayer.internal.model.impl.wrapper.ModelWrapper.validate(ModelWrapper.java:237) ~[coreserver.jar:?]
	at de.hybris.platform.servicelayer.internal.model.extractor.impl.DefaultModelExtractor.process(DefaultModelExtractor.java:50) ~[coreserver.jar:?]
	at de.hybris.platform.servicelayer.internal.model.impl.DefaultModelService.performPersistenceOperations(DefaultModelService.java:708) ~[coreserver.jar:?]
	at de.hybris.platform.servicelayer.internal.model.impl.DefaultModelService.saveAllInternal(DefaultModelService.java:703) ~[coreserver.jar:?]
	at de.hybris.platform.servicelayer.internal.model.impl.DefaultModelService.saveAll(DefaultModelService.java:683) ~[coreserver.jar:?]
	at de.hybris.platform.servicelayer.internal.model.impl.DefaultModelService.save(DefaultModelService.java:630) ~[coreserver.jar:?]
	at com.medion.usermanagement.facades.impl.MedionCustomerFacadeImpl.saveAndRefreshItem(MedionCustomerFacadeImpl.java:254) [classes/:?]
	at com.medion.usermanagement.facades.impl.MedionCustomerFacadeImpl.createCustomerInHybris(MedionCustomerFacadeImpl.java:43) [classes/:?]

[romitchhabra]

Are you logged in with test@test.com and get the logged in id in the error if you try with different customer? If yes then may be your custom code is trying to recreate a customer with the id same as logged in id and it is failing as no two customers can have same id.

If no then may be test@test.com is somewhere hardcoded in your code and code is trying to create a customer with that id. There shouldn't be a need to create a customer during checkout.