Due to a combination of design errors, bugs, and incorrect documentation, it is surprisingly hard to use .NET's HttpClient correctly. As a result, applications that appear to be working correctly ...

HttpClient was designed to be instantiated once and reused throughout the application’s lifecycle—you should not create a new HttpClient instance for every request that your application needs ...

You need to change the way you use HttpClient to keep your application from failing. And, if you're using ASP.NET Core, there's a tool that makes it considerably easier to do the right thing ...

The .NET Framework gives you three different ways to call a Web Service. However, depending on your scenario, the latest and greatest object isn’t necessarily your best choice.