> ## Documentation Index
> Fetch the complete documentation index at: https://docs.tryaeris.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Unclassified server error (INTERNAL)

> The tool failed with an error Aeris could not map to a specific taxonomy code.

## What it means

A `Throwable` escaped a tool handler without matching any of the strongly-typed exception classes. The message is redacted; the `request_id` on the outer response body is what our on-call needs to trace the failure in logs.

<Warning>
  If you keep seeing `INTERNAL` for a call that used to work, send us the `request_id` from the response and the tool name. Please do not paste the full response envelope into a public channel — `request_id` alone is enough for us to look it up.
</Warning>

## How to fix

* Retry once after `retry_after_ms` (default 10000ms) — a transient fault will usually clear.
* Capture the outer `request_id` in your logs alongside the failing tool and arguments so we can correlate.
* If it persists, contact Aeris support with the `request_id`.

## Response envelope

```json theme={"dark"}
{
  "ok": false,
  "request_id": "uuid-v4",
  "tool": "read_overview",
  "error_envelope": {
    "code": "INTERNAL",
    "message": "An unexpected error occurred.",
    "docs_url": "https://tryaeris.ai/docs/mcp/errors/internal",
    "retryable": true,
    "retry_after_ms": 10000,
    "details": {}
  }
}
```

`details` is intentionally empty — the underlying exception is not surfaced to callers by design.

## Related

* [`UPSTREAM_UNAVAILABLE`](/mcp/errors/upstream-unavailable) — fault outside Aeris.
* [`TIMEOUT`](/mcp/errors/timeout) — the tool ran but did not finish.