Could not resolve SDK "Microsoft.TeamsFx.Sdk". Outdated dependencies

[rido-min]

When I open the folder samples/bot-sso-adaptivecard/csharp in vscode with the toolkit installed I got these errors in the output window

2025-10-28 22:16:16.560 [info] C:\_code\Microsoft-Teams-Samples\samples\bot-sso-adaptivecard\csharp\M365Agent\M365Agent.ttkproj : error : Could not resolve SDK "Microsoft.TeamsFx.Sdk". Exactly one of the probing messages below indicates why we could not resolve the SDK. Investigate and resolve that message to correctly specify the SDK.
C:\_code\Microsoft-Teams-Samples\samples\bot-sso-adaptivecard\csharp\M365Agent\M365Agent.ttkproj : error :   SDK resolver "Microsoft.DotNet.MSBuildWorkloadSdkResolver" returned null.
C:\_code\Microsoft-Teams-Samples\samples\bot-sso-adaptivecard\csharp\M365Agent\M365Agent.ttkproj : error :   The NuGetSdkResolver did not resolve this SDK because there was no version specified in the project or global.json.
2025-10-28 22:16:16.930 [info] C:\_code\Microsoft-Teams-Samples\samples\bot-sso-adaptivecard\csharp\M365Agent\M365Agent.ttkproj : warning NU1503: Skipping restore for project 'C:\_code\Microsoft-Teams-Samples\samples\bot-sso-adaptivecard\csharp\M365Agent\M365Agent.ttkproj'. The project file may be invalid or missing targets required for restore. [C:\_code\Microsoft-Teams-Samples\samples\bot-sso-adaptivecard\csharp\BotSsoAdaptivecard.sln]
2025-10-28 22:16:16.935 [info]   Determining projects to restore...
2025-10-28 22:16:16.995 [info] C:\Program Files\dotnet\sdk\10.0.100-rc.2.25502.107\Sdks\Microsoft.NET.Sdk\targets\Microsoft.NET.EolTargetFrameworks.targets(32,5): warning NETSDK1138: The target framework 'net6.0' is out of support and will not receive security updates in the future. Please refer to https://aka.ms/dotnet-core-support for more information about the support policy. [C:\_code\Microsoft-Teams-Samples\samples\bot-sso-adaptivecard\csharp\BotSsoAdaptivecard\BotSsoAdaptivecard.csproj]
2025-10-28 22:16:17.769 [info]   All projects are up-to-date for restore.

Are these samples still maintained? I'm sueprised they still target dotnet6 that has been out of support since almost a year ago https://devblogs.microsoft.com/dotnet/dotnet-6-end-of-support/

Can we expect an update in this repo to use latest versions of dotnet and related dependencies in all samples?

[m365-agent-toolkit-assistant]

👋 Hi @rido-min,

Thank you for reporting this issue! We want to let you know that:

⏱️ Our team will personally review your issue
🎯 You can expect a response within 1 business day

✨ This is an AI-generated initial response
🤖 AI-Generated Preliminary Analysis:

You’re correct—most C# samples in the microsoft-teams-samples repo still target .NET 6, which is end-of-support (see official blog). This may result in SDK resolution issues like Could not resolve SDK "Microsoft.TeamsFx.Sdk" and warnings about outdated dependencies.

Similar issues are reported (#14665), and maintainers acknowledge the need for updates. There’s no ETA for a full upgrade, but you can:

• Set <Sdk> versions explicitly in .ttkproj or use a global.json file.
• Update local tooling to .NET 8 if supported; migrate your sample if possible.
• Follow the repo for maintenance updates.

If you encounter persistent errors, clear your NuGet cache (dotnet nuget locals all --clear) and re-install dependencies.

For official updates, comment on the relevant GitHub issue or create a new feature request.

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[microsoft-github-policy-service]

Hi @@rido-min! We will investigate and if we require further information we will reach out to you. Please use this link to escalate if you don't get replies in two working days.

Best regards, Teams Platform

[Prasad-MSFT]

Hi @rido-min, thanks for raising your issue. We will check this at our end and will update you accordingly. Could you please let us know whether you referring to below sample or any other?
https://github.com/OfficeDev/Microsoft-Teams-Samples/tree/main/samples/bot-sso-adaptivecard/csharp

[rido-min]

I was looking at that sample, but many others are outdated.

dotnet should target 9 or 10 (that will be GA in a few weeks)
we should use latest dependencies (when possible), specially BotFramework SDK packages

I suspect Node projects are in a similar state.

Maybe we can track two different issues, one for Microsoft.TeamsFx.Sdk errors and another one to update all the dependencies.