Using EnC triggers "Object reference not set to an instance of an object." in sample web app

[LyalinDotCom]

Version Used:
16.9.0 Preview 1.0 [30528.6.main]

Steps to Reproduce:

1. clone https://github.com/dotnet-architecture/eShopOnWeb or open my repro zip file (submitted directly to the dev via teams)
2. Open GetOrderDetailsHandler.cs and put a breakpoint on line 22 inside of "Handle" method (should be: "var customerOrders = await _orderRepository.ListAsync(new CustomerOrdersWithItemsSpecification(request.UserName));")
3. run the app in debug (F5)
4. Reach the code in step Update links in README.md with ported wiki content #2 to trigger breakpoint however you like or use the app navigation by using web app to: add an item to basket, checkout, login using demouser (listed in the page with username/password), click login, click pay now, click on username on top and go to order history then click detail
5. once you hit the breakpoint change line 23 (example below)

            //var order = customerOrders.FirstOrDefault(o => o.Id == request.OrderId);
            var order = customerOrders.First(o => o.Id == request.OrderId);

6. hit F5

Expected Behavior:

• App should resume running as the change is valid

Actual Behavior:

• web app crashes with object reference not set to an instance of an object exception

System.NullReferenceException
HResult=0x80004003
Message=Object reference not set to an instance of an object.
Source=Web
StackTrace:
at Microsoft.eShopWeb.Web.Features.OrderDetails.GetOrderDetailsHandler.d__2.MoveNext() in C:\Source\eShopOnWeb\src\Web\Features\OrderDetails\GetOrderDetailsHandler.cs:line 22