Page 735 - Bullet 1

[BobMolloy]

The code runs without error on Page 724, bullet 3. This error first appears on Page 726, bullet 7.

An unhandled exception occurred while processing the request.

InvalidOperationException: A second operation was started on this context instance before a previous operation completed. This is usually caused by different threads concurrently using the same instance of DbContext. For more information on how to avoid threading issues with DbContext, see https://go.microsoft.com/fwlink/?linkid=2097913.
Microsoft.EntityFrameworkCore.Infrastructure.Internal.ConcurrencyDetector.EnterCriticalSection()

Northwind.BlazorServer.Pages.Customers.OnParametersSetAsync() in Customers.razor

| 59. customers = await db.Customers.ToListAsync();

I eventually copied your Northwind.BlazorServer code to my solution and it worked. I can't figure out what the difference is. Of course, your code has moved on from page 726. What I know for sure is that, between pages 724 and 726, something went wrong.

I'm attaching the server output.
BlazorServer Server Output.txt

Here is my code. It's original location is C:\cs11dotnet7\PracticalApps
Northwind.BlazorServer.zip