A relationship multiplicity constraint violation occurred.an entityreference can have no more than one related object, but the query returned more than one related object.its a non-recoverable error.

CloudinaryImageURLsData is a Virtual Property

        public virtual CloudinaryImageURLsData CloudinaryImageURLsData { get; set; }

A relationship multiplicity constraint violation occurred: An EntityReference can have no more than one related object, but the query returned more than one related object. This is a non-recoverable error.

var res = (from a in vendorList
           join b in result on a.VendorId equals b.HotelCode
           select new HotelVendor { VendorId = a.VendorId, VendorName = a.VendorName, Address = a.Address, CloudinaryImageURLsData = a.CloudinaryImageURLsData, Country = a.Country, WeekEnd_Rank = a.WeekEnd_Rank }).ToList();