n8n troubleshooting: tested fixes for common errors
Every fix listed here was reproduced on a real n8n instance. Use these tested steps to diagnose the cause and get your workflow running again.
n8n forgot password: how to get back in (owner, member and 2FA)Locked out of self-hosted n8n? Tested fixes for a forgotten owner or member password, a reset email that never arrives, lost 2FA and 'Too many requests'.Tested on n8n 2.43.5 · 12 November 2026n8n secure cookie error: what it means and how to fix itFix n8n's 'configured to use a secure cookie' error the right way: HTTPS, localhost or N8N_SECURE_COOKIE, plus the X-Forwarded-For error behind Nginx.Tested on n8n 2.43.5 · 11 November 2026n8n "Connection lost" behind Nginx: tested causes and configWhy n8n shows Connection lost or Lost connection to the server behind Nginx, with the exact logs for each cause and a working Nginx config we tested.Tested on n8n 2.43.5 · 8 November 2026n8n database too big? Pruning, VACUUM and disk space, testedWhy n8n's database keeps growing, how much each execution adds, and the settings that shrink it: pruning, unsaved runs and SQLite VACUUM. With test results.Tested on n8n 2.43.5 · 6 November 2026n8n encryption key errors: mismatching keys and lost credentialsFix n8n's 'Mismatching encryption keys', 'signing.hmac cannot be read' and 'Credentials could not be decrypted' errors, with tested recovery steps.Tested on n8n 2.43.5 · 5 November 2026n8n Code node errors: 14 real messages and how to fix themExact n8n Code node error messages, from 'Code doesn't return items properly' to 'Module is disallowed' and 'access to env vars denied', with tested fixes.Tested on n8n 2.43.5 · 30 October 2026n8n Schedule Trigger not working? 8 causes we tested (2026)Why an n8n Schedule Trigger runs at the wrong time or not at all: the New York default timezone, TZ vs GENERIC_TIMEZONE, missed runs, cron errors and more.Tested on n8n 2.43.5 · 28 October 2026n8n webhook not working? 12 real errors and how to fix themThe exact n8n webhook error messages, what causes each one and how to fix it: test vs production URLs, 404s, localhost URLs, CORS, 403s and size limits.Tested on n8n 2.43.5 · 27 October 2026