Docker internal server error on Windows runners

[HofmeisterAn]

Description

For the last couple of weeks, I've been seeing flaky behavior when running simple integration tests with Testcontainers on the Windows runner. The tests haven't changed and used to be very stable, but recently they've started occasionally failing with:

Docker API responded with status code='InternalServerError', response='{"message":"hcs::CreateComputeSystem b2aa0b4dbe422b8a1e615030ee40189de7a192007597523f49039c43a0246bab: Incorrect function."}

Platforms affected

• Azure DevOps
• GitHub Actions - Standard Runners
• GitHub Actions - Larger Runners

Runner images affected

• Ubuntu 22.04
• Ubuntu 24.04
• Ubuntu Slim
• macOS 14
• macOS 14 Arm64
• macOS 15
• macOS 15 Arm64
• macOS 26
• macOS 26 Arm64
• Windows Server 2022
• Windows Server 2025
• Windows Server 2025 with Visual Studio 2026

Image version and build link

https://github.com/testcontainers/testcontainers-dotnet/actions/runs/24027006126/job/70067574197

Is it regression?

Yes, I believe this is a regression. It was stable for a very long time, but I don't know which image version introduced it.

Expected behavior

No internal server error when running the integration tests.

Actual behavior

Tests fail with internal server error.

Repro steps

Run the Testcontainers integration test (Testcontainers.Platform.Windows.Tests) a few times on the Windows runner.

[v-sergei-pyshnoi]

Hi @HofmeisterAn! Thanks for report, looks the its the same issue as here #13729. We are working on it will post updates in original issue. I am closing as duplicate, but if you have additional questions/concerns feel free to ask.

[HofmeisterAn]

@v-sergei-pyshnoi Thanks for sharing the issue.

FYI: I'm not sure it's an exact duplicate. Testcontainers detects an available Docker Engine (Docker doesn't seem to be stopped during runtime discovery). One test even passes, while the other two fail with the internal error mentioned above. Maybe that helps.