Docker / Docker

Docker Sandboxes v0.30.0 on Windows: Cannot Self-Connect to docker.sock (Daemon Running But Unreachable)

Fix Docker Sandboxes sbx run failing on Windows 11 because sandboxd in-process moby backend cannot connect to its own socket immediately after starting Includes evidence for Docker troubleshooting demand.

Source-backed Last updated May 23, 2026 1 source Needs local verification

Category: Docker
Error signature: ERROR: failed to create sandbox: create runtime: sandboxd error: status 500: failed to create network: Cannot connect to the Docker daemon at unix://...docker.sock. Is the docker daemon running?
Quick fix: Compare the failing environment with a known working setup, then change one configuration value at a time.
Updated: May 23, 2026
Verification status: Source-backed
Evidence: 1 public source URL

Before you change production

This page includes public source URLs in the imported troubleshooting record. Compare those references with your version and environment before applying changes.

Reproduce the smallest failing action and save non-secret logs before changing configuration.
Check versions for Docker, related SDKs, package managers, CI runners, and hosting providers.
Change one setting or dependency at a time, then rerun the same failing command or request.
Avoid destructive commands, credential rotation, billing changes, or security relaxations without a rollback plan.

What this error means

ERROR: failed to create sandbox: create runtime: sandboxd error: status 500: failed to create network: Cannot connect to the Docker daemon at unix://...docker.sock. Is the docker daemon running? is a Docker failure pattern reported for developers trying to fix docker sandboxes sbx run failing on windows 11 because sandboxd in-process moby backend cannot connect to its own socket immediately after starting. Based on the imported evidence, treat this as a tool-specific troubleshooting page rather than a generic API error.

Why this happens

GitHub Issue docker/sbx-releases#157 (May 2026): Docker Sandboxes v0.30.0 on Windows 11. sandboxd logs show socket serving correctly, but connecting goroutine 10ms later fails with daemon-not-running error. Secondary issue: stale socket files persist on restart ('file cannot be accessed by system'). Reproduced with Docker Desktop 29.4.3 + WSL2. Affects Docker Desktop/Sandboxes paid enterprise users.

Common causes

GitHub Issue docker/sbx-releases#157 (May 2026): Docker Sandboxes v0.30.0 on Windows 11. sandboxd logs show socket serving correctly, but connecting goroutine 10ms later fails with daemon-not-running error. Secondary issue: stale socket files persist on restart ('file cannot be accessed by system'). Reproduced with Docker Desktop 29.4.3 + WSL2. Affects Docker Desktop/Sandboxes paid enterprise users.

Quick fixes

Confirm the exact error signature matches ERROR: failed to create sandbox: create runtime: sandboxd error: status 500: failed to create network: Cannot connect to the Docker daemon at unix://...docker.sock. Is the docker daemon running?.
Check the Docker account, local tool state, and provider configuration involved in the failing workflow.
Compare the failing environment with a known working setup, then change one configuration value at a time.

Platform/tool-specific checks

Verify the command, editor, extension, or API client that produced the error.
Compare local settings with CI, deployment, or editor-level settings when the error appears in only one environment.
Avoid deleting credentials, local model data, or project settings until the failing scope is clear.

Step-by-step troubleshooting

Capture the exact error message and the command, editor action, or request that triggered it.
Check whether the failure is account/auth, quota/rate, model/provider, local runtime, or deployment configuration.
Review the source evidence below and compare it with your environment.
Apply one change at a time and rerun the smallest failing action.
Keep the working fix documented for the team or deployment environment.

How to prevent it

Keep provider/tool configuration documented.
Record non-secret diagnostics such as tool version, provider name, model name, and command path.
Add a lightweight check before CI or production workflows depend on the tool.

Diagnostic flow for this page

Match ERROR: failed to create sandbox: create runtime: sandboxd error: status 500: failed to create network: Cannot connect to the Docker daemon at unix://...docker.sock. Is the docker daemon running? exactly before applying the quick fix.
Compare the failing environment with Docker versions, account scope, provider settings, and deployment context.
Check the listed common causes in order, starting with the cause that best matches your logs.
Use the evidence status below to decide whether to confirm against public sources or official documentation.
Apply one reversible change, rerun the smallest failing action, and keep rollback notes.

FAQ

What does ERROR: failed to create sandbox: create runtime: sandboxd error: status 500: failed to create network: Cannot connect to the Docker daemon at unix://...docker.sock. Is the docker daemon running? mean in Docker?

ERROR: failed to create sandbox: create runtime: sandboxd error: status 500: failed to create network: Cannot connect to the Docker daemon at unix://...docker.sock. Is the docker daemon running? indicates the workflow described by "Docker Sandboxes v0.30.0 on Windows: Cannot Self-Connect to docker.sock (Daemon Running But Unreachable)" failed in a Docker context. Start by confirming the exact signature and the component that emitted it.

What should I check first for ERROR: failed to create sandbox: create runtime: sandboxd error: status 500: failed to create network: Cannot connect to the Docker daemon at unix://...docker.sock. Is the docker daemon running??

Check whether this cause matches your environment: GitHub Issue docker/sbx-releases#157 (May 2026): Docker Sandboxes v0.30.0 on Windows 11. sandboxd logs show socket serving correctly, but connecting goroutine 10ms later fails with daemon-not-running error. Secondary issue: stale socket files persist on restart ('file cannot be accessed by system'). Reproduced with Docker Desktop 29.4.3 + WSL2. Affects Docker Desktop/Sandboxes paid enterprise users.

Is the ERROR: failed to create sandbox: create runtime: sandboxd error: status 500: failed to create network: Cannot connect to the Docker daemon at unix://...docker.sock. Is the docker daemon running? guidance source-backed?

The "Docker Sandboxes v0.30.0 on Windows: Cannot Self-Connect to docker.sock (Daemon Running But Unreachable)" page is labeled source-backed. It has 1 public source URL from github.com, so use that evidence status when deciding how much additional verification you need.

When should I avoid the quick fix for ERROR: failed to create sandbox: create runtime: sandboxd error: status 500: failed to create network: Cannot connect to the Docker daemon at unix://...docker.sock. Is the docker daemon running??

For "Docker Sandboxes v0.30.0 on Windows: Cannot Self-Connect to docker.sock (Daemon Running But Unreachable)", avoid applying "Compare the failing environment with a known working setup, then change one configuration value at a time." when the error text differs, the affected version or provider is different, or the change would touch credentials, billing, DNS, production deploy settings, or irreversible data.

What should I collect before debugging ERROR: failed to create sandbox: create runtime: sandboxd error: status 500: failed to create network: Cannot connect to the Docker daemon at unix://...docker.sock. Is the docker daemon running??

For "Docker Sandboxes v0.30.0 on Windows: Cannot Self-Connect to docker.sock (Daemon Running But Unreachable)", collect the failing Docker command or request, non-secret configuration, versions, timestamps, request IDs when available, and the smallest reproduction that still triggers the signature.