DbEntityValidationException e ValidationException existe diferença ou

ValidationExcpetion (em System.Activies): The exception that is thrown when a workflow or activity is in an invalid state.

https://msdn.microsoft.com/en-us/library/system.activities.validationexception%28v=vs.110%29.aspx

ValidationExcpetion (em System.ComponentModel.DataAnnotation): Representa a exceção que ocorre durante a validação de dados de um campo quando o ValidationAttribute classe é usada.

https://msdn.microsoft.com/pt-br/library/system.componentmodel.dataannotations.validationexception%28v=vs.110%29.aspx

DbEntityValidationException (em System.Data.Entity.Validation): Represents an exception thrown from SaveChanges when the validation of entities fails.

https://msdn.microsoft.com/en-us/library/system.data.entity.validation.dbentityvalidationexception%28v=vs.113%29.aspx