this error actually occurs in two different places withing my web application.

This event fires in code behind file when a user clicks insert link button.
Line of code that fails is below
context.tblUPCCodes.AddObject(upcProfile);

protected void UpcInsertLinkButton_Click(object sender, EventArgs e){
                       

                        try
                        {
                                
                                // Create an entity type
                                upcProfile = new tblUPCCode();


                                // Set to false on insert
                                upcProfile.Obsolete = false;

                                // Set to empty
                                upcProfile.Wh_ID = String.Empty;

                                // Set properties for UPC entity
                                upcProfile.RTD = cboxRTD.Checked;
                                upcProfile.Export = cboxExport.Checked;
                                upcProfile.COORequired = cboxCOO.Checked;
                                upcProfile.UPCCode = tboxUpcProfileCode.Text.Trim();
                                upcProfile.AltUPC = tboxUpcProfileAlternateCode.Text.Trim();
                                upcProfile.GlobalUPC = tboxUpcProfileGlobalNum.Text.Trim();
                                upcProfile.ShelfLife = Convert.ToInt32(tboxUpcProfileShelfLife.Text.Trim());
                                upcProfile.ForeignFlavorName = tboxUpcProfileForiegnFlavName.Text.Trim();
                                upcProfile.Barcode = tboxUpcProfileBarcode.Text.Trim();

                                // Get primary keys of related entities
                                CompanyProfilePK = Convert.ToInt32(ddlCompanies.SelectedValue);
                                BottleProfilePK = Convert.ToInt32(ddlBottles.SelectedValue);
                                FormulaProfilePK = Convert.ToInt32(ddlFormulas.SelectedValue);
                                FillerProfilePK = Convert.ToInt32(ddlFillers.SelectedValue);
                                PalletizerProfilePK = Convert.ToInt32(ddlPalletizers.SelectedValue);
                                LabelerProfilePK = Convert.ToInt32(ddlLabelers.SelectedValue);
                                CaseformerProfilePK = Convert.ToInt32(ddlCaseFormers.SelectedValue);


                                upcProfile.CompanyID = CompanyProfilePK;
                                upcProfile.BottleTypeID = BottleProfilePK;
                                upcProfile.FormulaID = FormulaProfilePK;
                                upcProfile.FillerProfileID = FillerProfilePK;
                                upcProfile.PalletizerProfileID = PalletizerProfilePK;
                                upcProfile.LabelerProfileID = LabelerProfilePK;
                                upcProfile.CaseFormerProfileID = CaseformerProfilePK;

                                using (var context = new ProductSpecSheetsEntities()){


                                        // Object Set adds entity type to entity
                                        context.tblUPCCodes.AddObject(upcProfile);


                                        // Context Object save entity and inserts new row in DB table
                                        context.SaveChanges();


                                        // Now we can extract the primary key for the inserted record from SQL DB
                                        UpcProfilePK = upcProfile.UpcID;

                                }
                        }
                        catch (Exception exception) {
                                
                                throw exception.InnerException;
                        }