Free checklist

n8n webhook and queue troubleshooting checklist

A practical checklist for production-style n8n failures: webhook 404s, wrong public URLs, reverse proxy issues, queue mode, workers, Redis, Postgres, OAuth callbacks, CORS, rate limits, and invalid JSON.

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Webhook URL and mode

Confirm whether the caller is using the test URL or production URL.
If using the production URL, confirm the workflow is active.
Check the Webhook node path and HTTP method.
For self-hosted n8n, confirm WEBHOOK_URL and the public domain match the real external URL.

Reverse proxy and browser access

Confirm the reverse proxy forwards webhook paths to n8n.
Check whether the proxy rewrites or strips paths.
For browser calls, confirm the Webhook node allowed origins and proxy CORS headers.
Test externally, not only from the server.

Queue mode and workers

Confirm main and worker processes use EXECUTIONS_MODE=queue.
Check Redis host, port, password, and database from both main and worker containers.
Confirm workers share the same n8n database and N8N_ENCRYPTION_KEY.
Run a small workflow and verify a worker completes the execution.

Data and payload failures

For invalid JSON, inspect the exact runtime payload, not just the template.
For expressions, confirm referenced nodes executed on the current branch.
For rate limits, add delay, batching, or Loop Over Items before retrying at scale.
For OAuth callbacks, copy the exact callback URL from n8n into the provider app.

When To Use It

Use this when a workflow worked in the editor but fails from an external app, when jobs stay queued, when workers look healthy but do not process executions, or when browser/API calls fail before the workflow logic is reached.

This is an independent third-party checklist. It links back to source-backed Workflow Fixes pages and official n8n documentation for verification.

Related Fix Pages

n8n Webhook 404 Wrong URL, inactive workflow, method mismatch, or reverse proxy path problems. n8n Worker Not Processing Jobs Queue mode, Redis, database, worker command, and encryption key checks. n8n Rate Limit Error Retry delay, batching, Loop Over Items, Wait, and idempotency checks. n8n Invalid JSON Runtime payload, raw body, expression, quote, and structured field checks.