# Troubleshooting

> Common startup and connection failures.

Canonical: https://keta1930.github.io/icml2026-mcp/en/docs/operations/troubleshooting



## `Not Acceptable: Client must accept text/event-stream` [#not-acceptable-client-must-accept-textevent-stream]

`/mcp` is a Streamable HTTP MCP endpoint, not a web page. A normal browser request does not send the required `Accept` header, so this response is expected. Add the URL through an MCP client. For a transport-level check:

```bash
curl -i -H 'Accept: text/event-stream' \
  https://icml.agent4sci.com:20441/mcp
```

## Readiness returns 503 [#readiness-returns-503]

Check that Milvus is healthy, `current.json` exists, and its collection is present:

```bash
docker compose -f deploy/compose.yaml -f deploy/milvus.compose.yaml ps
docker compose -f deploy/compose.yaml -f deploy/milvus.compose.yaml logs icml-mcp standalone
```

## Search returns an embedding error [#search-returns-an-embedding-error]

Confirm the secret file is readable inside the application and the key can call `qwen3.7-text-embedding` in the Beijing region.