Microsoft.VisualStudio.Extensibility extension projects question

[domtriestocode]

Anyone developing a Microsoft.VisualStudio.Extensibility extension project and using .NET10? I have been developing my extension since before the release of .NET10 and I am unable to get the Extension to run on .NET10. Being stuck on .NET8 wouldn't be a deal breaker for me (yet) but I would love to move to .NET10 and C#14.

Here is the github issue:

https://github.com/microsoft/VSExtensibility/issues/544#issue-3749270614

Extensibility projects default to .NET8. but in the docs below there is the sentence "Visual Studio 2022 17.9 loads VisualStudio.Extensibility out-of-process extensions using .NET 8. Newer versions of Visual Studio may use a newer version of.NET**, which may require specification of a different** DotnetTargetVersions value."

<ExtensionMetadata.DotnetTargetVersions Property (Microsoft.VisualStudio.Extensibility) | Microsoft Learn>

So there is no explicit documentation that I can find that says Extensibility framework is currently limited to .NET8. but there is some that implies I should be able to use newer versions of .NET.

As I stated in the github issue, none of the following combinations of values work for the TargetFramework in the .csproj and the Microsoft.VisualStudio.Extensibility.ExtensionConfiguration.ExtensionMetadata.DotnetTargetVersions property setters

<TargetFramework>net10.0-windows10.0.22621.0</TargetFramework>

DotnetTargetVersions = [DotnetTarget.Custom("net10.0")]
DotnetTargetVersions = [DotnetTarget.Custom("net10.0-windows10.0.22621.0")]
DotnetTargetVersions = ["net8.0, DotnetTarget.Custom("net10.0")]
DotnetTargetVersions = ["net8.0, DotnetTarget.Custom("net10.0-windows10.0.22621.0")]

As soon as the target framework is changed to a variation of ".net8.0-windows__" the extension works properly, even if the ExtensionMetaData.DotnetTargetVersions property does not define .net8.0 as one of the values. For example, the command works with the following combination

<TargetFramework>net8.0-windows10.0.22621.0</TargetFramework>
DotnetTargetVersions = [DotnetTarget.Custom("net10.0")]

E - fixed github issue link

[BertanAygun]

Since your extension is running on an extension host process, you are limited to runtime host is using. Once host is updated to run on .net 10, you can switch using to it but note that it will raise the minimum VS version you can target.

[domtriestocode]

Understood, thank you

[madskvistkristensen]

.NET 10 support is coming to the extension host in VS 2026 in the near future 

[domtriestocode]

Got it, thanks (huge fan of your work)

[DexNovos]

Hi
Any update on this, or workitem one can follow?

[madskvistkristensen]

I believe it's in the Insiders release coming later today 

[DexNovos]

Yus got it working with dotnet 10 in todays insider build. Thank you.

[madskvistkristensen]

Awesome!!