Describe the bug

The following error messages are encountered when I copied and pasted the first code snippet provided in the "Explore C# 6 - C# interactive C# tutorial"

(1,1): error CS8652: The feature 'using declarations' is currently in Preview and unsupported. To use Preview features, use the 'preview' language version.
(1,7): error CS0118: 'System' is a namespace but is used like a type
(1,13): error CS0210: You must provide an initializer in a fixed or using statement declaration
(1,13): error CS1001: Identifier expected
(1,1): error CS1513: } expected
(27,14): error CS0542: 'Program': member names cannot be the same as their enclosing type

Did this error occur while using dotnet try or online?

• [ x ] dotnet-try
• [ x ] online

What kind of error was it?

• [ x ] User Interface (UI): For example the output never displayed
• Service Error: For example "The service is temporarily unavailable. We are working on it"
• [ x ] Other:

(1,1): error CS8652: The feature 'using declarations' is currently in Preview and unsupported. To use Preview features, use the 'preview' language version.
(1,7): error CS0118: 'System' is a namespace but is used like a type
(1,13): error CS0210: You must provide an initializer in a fixed or using statement declaration
(1,13): error CS1001: Identifier expected
(1,1): error CS1513: } expected
(27,14): error CS0542: 'Program': member names cannot be the same as their enclosing type

Screenshots

Steps to reproduce:

1. Navigate to https://docs.microsoft.com/en-us/dotnet/csharp/tutorials/exploration/csharp-6?tutorial-step=1
2. Click Focus Mode
3. Copy the first code snippet provided in the web page.
4. Paste the code in the .NET editor

Actual Result:

(1,1): error CS8652: The feature 'using declarations' is currently in Preview and unsupported. To use Preview features, use the 'preview' language version.
(1,7): error CS0118: 'System' is a namespace but is used like a type
(1,13): error CS0210: You must provide an initializer in a fixed or using statement declaration
(1,13): error CS1001: Identifier expected
(1,1): error CS1513: } expected
(27,14): error CS0542: 'Program': member names cannot be the same as their enclosing type

Please complete the following:

• OS
  • [ x ] Windows 10
  • macOS
  • Linux (Please specify distro)
  • iOS
  • Android
• Browser
  • [ x ] Chrome
  • [ x ] Edge
  • Safari