---
title: Troubleshoot Topic Registry
slug: solutions/topic-registry/troubleshoot
description: Diagnose connection, discovery, and live-data problems in Topic Registry.
createdAt: 2026-11-10T01:21:10.750Z
---

Start by checking the Topic Registry container logs and the component retrieval results. Record the Topic Registry version and Litmus Edge version when requesting support.

## Cannot locate Litmus Edge

The message `Cannot locate Litmus Edge` means internal gateway detection found no usable address, or external mode has no URL.

For an internal installation, set `EDGE_DOCKER_GATEWAY_IP` to the Litmus Edge instance's Docker gateway. For an external installation, set `EDGE_URL` to its HTTP or HTTPS origin. Recreate the container with the corrected environment, then select **Test Connection**.

## Cannot reach Litmus Edge API

Check the URL shown in the error. Internal installations use the Docker gateway. External installations use the configured Litmus Edge hostname and API port.

If the instance uses a self-signed certificate, set `EDGE_VERIFY_TLS=false`. Recreate the container and test the connection again. This setting controls certificate verification for connections to Litmus Edge.

## API connection returns HTTP 401

Check the Litmus Edge API token and its permissions when the failing URL belongs to Litmus Edge.

Check `X_LITMUS_KEY` when the failing URL belongs to Topic Registry. External API clients must send that secret in the request header. Reload the browser after changing the secret.

## NATS connection fails

Confirm that `EDGE_CONNECTION_MODE` matches the deployment. Internal mode sends no NATS credentials and uses no NATS TLS. External mode requires a valid `EDGE_NATS_TOKEN` and a reachable NATS proxy on port `4222`.

Retest the connection after correcting the settings. Then open a known topic and confirm messages in **Live Stream**.

## A component fails during retrieval

Open the failed component and read its reported error. Check its API-token permissions and refetch the component data after correcting the cause. Successful retrieval for other components does not make a failed component's inventory complete.

## A tag appears unused but an application consumes it

Check the application's subscriptions and any dynamically constructed topic names. Configuration discovery does not identify every consumer.

To capture messages from a custom topic prefix, add a namespace in **Marketplace** or **Flows**. A namespace records matching messages, but does not prove which application consumes them.

## A live stream connects but shows no values

Confirm that the source publishes to the exact topic you opened. A connected NATS session does not prove that the source is publishing. Select **Stop Streaming** when you finish investigating.