Organization Service Create Entity returns "The unit id is missing"

Question

I have a silverlight application which i'm using as a web resource for CRM 2015, I have used this tutorial to use async and await keywords. I can retrieve entities successfully. However, I'm trying to create entities into the CRM but for some reason I'm getting the error message "The unit id is missing".

I tried a very simple entity creation just for testing and still the same result, here is my code:

 Guid ProductCategoryGuid = new Guid(mytextblock.Tag.ToString());
                Money Amount= new Money();
                Amount.Value = Decimal.Parse(mytextblock.Text);

                EntityReference Opportunity = new EntityReference();
                Opportunity.Id = OpportunityGuid;
                Opportunity.LogicalName = "opportunity";

                EntityReference Product = new EntityReference();
                Product.Id = SelectedProductGuid;
                Product.LogicalName = "product";

                EntityReference ProductCategory = new EntityReference();
                ProductCategory.Id = ProductCategoryGuid;
                ProductCategory.LogicalName = "new_productcategory";

                Entity OpportunityProduct = new Entity();
                OpportunityProduct.LogicalName = "opportunityproduct";

                OpportunityProduct["new_productcategory"] = ProductCategory;
                OpportunityProduct["productid"] = Product;
                OpportunityProduct["opportunityid"] = Opportunity;
                OpportunityProduct["baseamount"] = Amount;

                await service.Create(OpportunityProduct);

EDIT:

I'm not sure if that helps, but I used Fiddler to debug my application and I got this Error: "The unit id is missing".

Answer 1

It turns out I hadn't added the uom id for the opportunity product. I retrieved the defaultuomid of the product i'm referring to in the OpportunityProduct and then creation was completed successfully