---
id: SAIFTRBL0015
moved_from:
  - guides/troubleshooting/vstest-target-not-supported-dotnet-10.md
title: VSTest target is no longer supported on .NET 10
description: Migrate to native Microsoft Testing Platform, or pin xunit.v3 to 3.2.2 on a legacy VSTest-based project, when a .NET 10 build cannot run tests through the VSTest target.
tags:
  - troubleshooting
  - build
  - pipelines
---

# VSTest target is no longer supported on .NET 10

**One-sentence summary:** a newer `xunit.v3` release brings in Microsoft.Testing.Platform 2.x, which dropped VSTest support on .NET 10; migrate the project to native MTP, or pin `xunit.v3` to `3.2.2` if it must stay on VSTest.

---

## 🚨 Symptom

The unit-test step fails in Azure DevOps even though the tests pass locally:

```text
error : Testing with VSTest target is no longer supported by Microsoft.Testing.Platform on .NET 10 SDK and later. If you use dotnet test, you should opt-in to the new dotnet test experience. For more information, see https://aka.ms/dotnet-test-mtp-error
```

The failure occurs while MSBuild invokes the `VSTest` target for a .NET 10 test project.

---

## 📌 Applies to

| Aspect | Value |
| ------ | ----- |
| **Component** | Legacy VSTest-based .NET unit-test projects (no `global.json` MTP opt-in) |
| **Forge versions** | Forge 3 projects targeting .NET 10 that predate the native-MTP templates |
| **Related versions** | `xunit.v3` newer than `3.2.2`; observed with `Microsoft.Testing.Platform` `2.3.3` |

Apps generated from the current `saif-feature-base` template already ship a `global.json` with `{ "test": { "runner": "Microsoft.Testing.Platform" } }` and pin `xunit.v3` 4.x, so they never hit this error. If you see it in such an app, the `global.json` opt-in is missing rather than the `xunit.v3` version being wrong.

---

## 🧠 Cause

Updating `xunit.v3` to 4.x brings in `Microsoft.Testing.Platform` 2.x, which dropped VSTest support entirely. Anything that still drives tests through the MSBuild `VSTest` target, including a plain `dotnet test` without the `global.json` opt-in, fails on the .NET 10 SDK. Local runs can pass when they use a different SDK or test execution path, so the incompatibility may appear only in a build.

Forge's own Azure DevOps pipeline templates no longer call `dotnet test`: they build each test project and run the built assembly directly under `dotnet-coverage`, so they are unaffected by the VSTest/MTP split. The `global.json` opt-in only changes local `dotnet test` invocations.

---

## ✅ Fix

### Preferred: migrate the project to native MTP

Keep `xunit.v3` on 4.x and opt the repo into the native `dotnet test` experience with a repo-root `global.json`:

```json title="global.json"
{ "test": { "runner": "Microsoft.Testing.Platform" } }
```

Add a `Microsoft.Testing.Extensions.TrxReport` reference (MTP-2.x compatible, for example `2.4.0`) to each test project that needs TRX output, and drop `coverlet.collector` and `xunit.runner.visualstudio`, both of which are VSTest-only. Coverage comes from [`dotnet-coverage`](https://learn.microsoft.com/dotnet/core/additional-tools/dotnet-coverage), which instruments the test process and needs no package reference. This is exactly what the current templates scaffold; see [Test Execution: Native Microsoft Testing Platform (MTP)](../build/testing/index.md#test-execution-native-microsoft-testing-platform-mtp) and the `dotnet-testing` skill's VSTest-to-MTP migration notes.

Under MTP, `dotnet test` requires `--project`, `--solution`, or `--test-modules` instead of a positional project path:

```powershell
dotnet test --project <path-to-test-project> --report-trx
```

### Fallback: pin `xunit.v3` to `3.2.2` on a legacy VSTest project

If the repository must keep running the VSTest test host, pin `xunit.v3` to the last 3.x release instead of migrating. This is a holding position, not the recommended end state.

If the repository uses central package management, update `Directory.Packages.props`:

```xml
<PackageVersion Include="xunit.v3" Version="3.2.2" />
```

If the test project manages its own package versions, update its `.csproj` file:

```xml
<PackageReference Include="xunit.v3" Version="3.2.2" />
```

Restore packages and commit the updated lock file if the repository uses one:

```powershell
dotnet restore
```

---

## 🔬 Verify

Re-run the build. The test step should complete without the `Testing with VSTest target is no longer supported` error. After migrating to MTP, `dotnet test --project <path> --report-trx` should discover and run tests locally; note that MTP treats a run that discovers zero tests as a failure (exit code 8), so give an intentionally empty test project a placeholder test.

---

## 📚 Related

- [Test Execution: Native Microsoft Testing Platform (MTP)](../build/testing/index.md#test-execution-native-microsoft-testing-platform-mtp)
- [API testing with Aspire](../build/testing/api-integration-testing.md)
- [Version compatibility matrix](../reference/version-compatibility.md)
- [Testing with `dotnet test`](https://aka.ms/dotnet-test-mtp-error)
- [Source Azure DevOps build](https://dev.azure.com/SAIFCorporation/Customer/_build/results?buildId=199912&view=logs)