Updated at Apr 22, 2019

Updated to more better workaround written on comments, thank you @kodamasakuno .


The body of this article

This article is as of .NET Core 3.0 Preview 3.


If you write a code in .NET Framework WPF app like as below:

Process.Start("https://example.com"); // Open the URL using default browser

It works fine. However, in .NET Core 3.0, the code occurred following exception:


  Message=The system cannot find the file specified.

The cause of this issue, it is changing default value in UseShellExecute property at ProcessStartInfo class. .NET Framework is true, but .NET Core is false.

So, the workaround is following code:

Process.Start(new ProcessStartInfo("https://example.com") { UseShellExecute = true });

It works fine.test.jpg


Happy coding!!


Old article

In this case, the workaround is to use Launcher.LaunchUriAsync method that is WinRT APIs.

At first, add following references to your project file.

  <PackageReference Include="System.Runtime.WindowsRuntime" Version="4.3.0" />

  <Reference Include="Windows">
    <HintPath>$(MSBuildProgramFiles32)\Windows Kits\10\UnionMetadata\10.0.17763.0\Windows.winmd</HintPath>

And then, replace Process.Start to Launcher.LanuchUriAsync.

private async void FooButton_Click(object sender, RoutedEventArgs e)
    await Launcher.LaunchUriAsync(new Uri("https://example.com"));

It works fine.👍




Occasional Visitor

Presumably that would make it Windows 10 only?


Yes, the workaround can be used on Windows 10.

On WIndows 7 case, I guess you can use following workaround.

Process.Start("cmd.exe /c start https://example.com");

However, It is not valid on Windows 10 S mode(Running on S mode is Microsoft store requirement), because S mode can not use cmd.exe.

Occasional Visitor

Here is a better workaround. Just the following line.

Process.Start(new ProcessStartInfo("https://example.com") { UseShellExecute = true });

The simple reason is because the default value of ProcessStartInfo.UseShellExecute is false in .Net Core while it's true in .Net Framework.



Thank you for telling me the workaround.

I have updated the article.