> Index of all guides: https://hither.dev/llms.txt. Agents start at https://hither.dev/skill.md.

# Troubleshooting

For people and agents when setup or a call goes wrong. Find the symptom, then do what the last column says.

| Symptom | Likely cause | What to do |
| --- | --- | --- |
| The app shows no Hither tools | The server isn't added, is off, or the app hasn't reloaded | Add `https://hither.dev/mcp` from [apps](apps.md), turn it on, and reload the app. |
| Sign-in fails or loops | Wrong address, an old app, or an unsupported OAuth mode | Check the address is exactly `https://hither.dev/mcp`, update the app and reconnect. See [OAuth details](clients.md#oauth-details-for-client-developers). Never put a token in a connector. |
| `invalid_grant` with `reconnect_required` | The OAuth authorization ended | Sign in again. The computer is fine. |
| `devices` is empty or the computer never appears | Approval isn't finished, or the helper isn't running | Ask the person to finish approving. `hither status` on the computer shows the helper. |
| The setup link expired | It passed its [time limit](how-it-works.md#limits) | Get a new one: `connect_computer` again, or `POST /api/connect/request` with the same agent token. |
| `permission_required` or `device_operation_not_allowed` | The connection doesn't allow that operation or folder | Tell the person which permission the task needs. They change it in the dashboard or on the setup page. |
| `connection_limit_or_identity_expired` | An anonymous agent has 5 live connections or made 20 today, or its REST token expired | Finish or drop a connection, or wait. A REST agent past 24 hours starts again only if the person asks. |
| `account_agent_required` or `anonymous_oauth_required` | Only an account agent can ask to keep access, and only an anonymous MCP agent can be claimed | See [keep access](https://hither.dev/skill.md#keep-access). A REST agent can't do either. |
| `extension_unavailable_or_update_helper` | The connection ended too long ago, ended another way, or the helper predates this feature | Tell the person. They can run setup again on the computer to update the helper. |
| `sandbox.blocked: true` | The Terminal sandbox refused a write, a credential read or a local address | Tell the person what `stderr` says was refused. Only they can allow full access. |
| `update_helper_for_*` | The helper is older than the feature | Ask the person to run setup again on the computer. |
| `device_offline` | The computer is asleep or offline | Drop the work or [queue it](operations.md#when-the-computer-is-offline). |
| `outcome_unknown` | The call may have run | Don't retry. [Resolve it](operations.md#resolve-an-uncertain-outcome). |
| `401 unauthorized` | The credential expired or was revoked | OAuth: let the client refresh, or sign in again. REST: the 24-hour token ended, so start again only if the person asks. |
| `browser_installing` | Chromium is still downloading | Wait a few seconds and call again. |
| HTTP 403, Cloudflare `1010` | Cloudflare blocked the client | Send a `User-Agent` that names your agent. [Details](guest-connections.md#errors). |

Still stuck? With the person's approval, [report it](skill-feedback.md).