New C# 8 Features Unusable on Try.Dot.NET

[TheFanatr]

Describe the bug

On the Try .NET website, the new features introduced with C# 8 cannot be used.

Did this error occur while using dotnet try or online?

• [ ] dotnet-try
• [x] online

What kind of error was it?

• [ ] 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: The feature is currently in Preview and *unsupported*. To use Preview features, use the 'preview' language version.

Screenshots

Please complete the following:

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

[BillWagner]

This may be because of the changes in how the language version is configured. If the target framework isn't netcoreapp3.0, C# 8 is off by default.

[mairaw]

@jonsequitur what's the story for this issue? We got a similar feedback for our website recently: https://github.com/dotnet/website/issues/2385

I'm closing that one as duplicate of this.

[jonsequitur]

We're working on updates to Try .NET to bring it up to C# 9 and use the release version of Blazor WebAssembly. I'll post updates when we have a better sense of the timeline.