---
title: "Troubleshooting"
slug: "polarity-mcp-troubleshooting"
description: "Troubleshoot common Polarity MCP issues including connection refused errors, 401 unauthorized responses, and token validation problems."
tags: ["401 unauthorized", "authentication issues", "Bearer token", "debug", "error resolution", "MCP connection refused", "token error", "troubleshooting"]
updated: 2026-07-29T19:32:05Z
published: 2026-07-29T19:32:05Z
canonical: "knowledge.threatconnect.com/polarity-mcp-troubleshooting"
---

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

# Troubleshooting

## MCP Connection Refused or 401 Unauthorized

- Verify the token was obtained from the correct Polarity Server.
- Check that the token has not been disabled by an admin.
  - Log in to the Polarity UI with the same credentials to confirm the account is active.
- Confirm the Authorization: Bearer <token> header is present and correctly formatted.

## Tool List Is Empty

This can occur if authentication succeeded but tool registration failed during server initialization.

- Review the server logs for errors from `Polarity.Conversations.Mcp.Server`.
- Confirm the user account is valid and the resolved user record was assigned to the MCP frame.
  - Look for the `MCP Server initializing for user:` log line.

## `do\_integration\_lookup` Returns " `Integration not available`"

- The passed integration ID is not on the user's allowed list.
  - This can mean the user is not subscribed to the integration, the integration is not running, or the integration ID has changed (for example, after an upgrade).
- Call `list\_available\_integrations` first and use the IDs returned from that call.
  - Integration IDs include version numbers and runtime node identifiers and change when the integration is upgraded or restarted.

## Lookup Returns No Results

- Confirm the entity type in your query matches entity types supported by the integration.
  - Check the entity types and custom types fields in the `list\_available\_integrations` response.
- The third-party data source may genuinely have no data for the queried entity.
  - This is *not* an error.
- Confirm the integration worker is healthy.
  - An integration stuck in a degraded state may accept lookup requests but return empty results.

## AI Chat Returns Provider Error

- Verify the API key in Model Settings is valid and has not been revoked by the provider.
- Check that the selected model is available in your provider account and region.
- For Bedrock, confirm the AWS credentials have the correct IAM permissions to invoke the selected model in the configured region.
- Use the “Test Chat” button in Model Settings to isolate provider connectivity from Polarity-side issues.

## Reducer Logs Show No Reduction

If log entries show `reduction\_percentage: 0` or the reducer messages do not appear at all, the integration may not have a details reducer registered.

- Check the integration's configuration for a `\_reducers` key with a nested " `details`" DSL pipeline.
- Confirm `mcp\_reducers\_enabled: true` is set in the `polarity\_integrations` application config for the running environment.