There is no Functions runtime available that matches the version specified in the project.

Question

There is no Functions runtime available that matches the version specified in the project.

Maurya, Pranjal 0

after upgrade to azure function app project to dot net 10 : it saying There is no Functions runtime available that matches the version specified in the project. updated core function tool too.

Gursimran Singh 570 Reputation points Microsoft External Staff Moderator

2026-08-24T14:32:50.96+00:00

If the above steps did not help resolve your issue, please feel free to share the details in a private message so we can proceed with further troubleshooting over a Teams call. I am happy to connect with you on Teams to investigate and resolve the issue.

2 answers

Your answer

Gursimran Singh 570 Reputation points Microsoft External Staff Moderator

2026-08-24T14:32:50.96+00:00

If the above steps did not help resolve your issue, please feel free to share the details in a private message so we can proceed with further troubleshooting over a Teams call. I am happy to connect with you on Teams to investigate and resolve the issue.

Answer 1

Hi @Maurya, Pranjal ,

Welcome to the Microsoft Q&A Platform! Thank you for asking your question here.

Root Cause

Azure Functions supports .NET 10 exclusively through the isolated worker process model. The in-process model was never updated to support .NET 10, so if any part of the project — the SDK reference, the target framework declaration, or the local configuration — still reflects the in-process model, the Functions host cannot resolve a matching runtime, producing this exact error regardless of how recently Core Tools or the Functions extension has been updated.

A secondary and equally common root cause is that the locally cached Azure Functions Tools metadata in Visual Studio (used to determine which runtime builds are available) has not been refreshed since the .NET 10 upgrade, so Visual Studio evaluates the project against an outdated list of supported versions.

Troubleshooting Steps

Verify the project is configured for the isolated worker model. In the .csproj file, confirm:

xml

Note: AzureFunctionsVersion must be lowercase v4. A value of V4 (capitalized) has been confirmed to produce this same error.

Confirm the correct SDK reference is present. The project should reference Microsoft.Azure.Functions.Worker.Sdk, version 2.0.5 or later. If Microsoft.NET.Sdk.Functions is still referenced, the project has not fully migrated off the in-process model, which does not support .NET 10 under any configuration.
Update Azure Functions Core Tools to the latest 4.x release, since .NET 10 support was only introduced in recent builds:

   npm install -g azure-functions-core-tools@4 --unsafe-perm true

Verify local.settings.json. The FUNCTIONS_WORKER_RUNTIME value must be set to "dotnet-isolated". A residual value of "dotnet" from the prior configuration will cause the host to attempt to resolve an in-process runtime, which does not exist for .NET 10.
Clear the cached Azure Functions Tools metadata in Visual Studio. Close Visual Studio, delete the folder:

   %LocalAppData%\AzureFunctionsTools

Reopen the solution and rebuild. Visual Studio will re-download the runtime metadata corresponding to the current project configuration, resolving cases where the tooling cache — rather than the project itself — is the source of the mismatch.

If the error also occurs during deployment to Azure (rather than only locally), confirm the hosting plan supports .NET 10. .NET 10 is supported on the isolated worker model across all Windows and Linux Functions hosting plans except Linux Consumption. Apps currently on Linux Consumption must migrate to Flex Consumption to run on .NET 10.

Please "upvote" if the information helped you. This will help us and others in the community as well.

Answer 2

Azure Functions does not support using .NET 10 with the in-process model. For Functions runtime 4.x:

Isolated worker model supports net10.0 as preview.
In-process model supports net8.0 or net6.0 only.

If the project was upgraded to .NET 10 and still uses the in-process model, Visual Studio/Core Tools can show: There is no Functions runtime available that matches the version specified in the project.

Use one of these supported fixes:

If the app is in-process, change back to a supported target
- In the .csproj, use:
```
   <TargetFramework>net8.0</TargetFramework>
   <AzureFunctionsVersion>v4</AzureFunctionsVersion>
```
- Ensure AzureFunctionsVersion is exactly v4.
If .NET 10 is required, migrate the app to the isolated worker model
- .NET 10 is supported only on the isolated worker model, not in-process.
Verify the app is targeting Functions runtime 4.x
- Azure Functions currently supports only version 4.x of the runtime host.
- In Azure, confirm the app runtime version in the Azure portal.
Match local tools to the major runtime version
- Local Azure Functions Core Tools must match the major runtime version used by the function app in Azure.
- In Visual Studio, Functions 4.x Core Tools are included in the Azure Functions and Web Jobs Tools extension.
If the error started after changing versions and functions stopped loading, rebuild and redeploy
- Ensure deployed artifacts match the new configuration.
- If needed, revert to the previous working version, then complete the upgrade with a proper rebuild and redeploy cycle.

For a .NET 10 project, the key check is whether the app is still configured as in-process. If it is, either move to isolated worker or retarget to .NET 8.