How to throw a custom error in an n8n Code node inside a loop
Two patterns for collecting per-item errors in n8n loops without halting the workflow - including the silent colon-truncation bug in Continue mode.
Topic
n8n
n8n automation platform
Automate social media posting with n8n: full workflow walkthrough
Build one n8n workflow that reads a Google Sheets queue and posts to all four major platforms -- including the Instagram two-step container trick and Meta token renewal.
n8n Code node: how to install and use external npm packages
Allowlist and install external npm packages for the n8n Code node - including the n8n 2.x task-runner gotcha most guides skip.
How to fix n8n nested loops: the inner loop retains completed state bug
The inner Loop Over Items node skips processing after the first outer iteration because it retains its completed state. Here are the three fixes, including the Done-branch chain pattern that avoids the bug entirely.
Send automated emails with n8n: SMTP, Gmail, and templates
Set up Gmail SMTP credentials, build HTML templates with dynamic data, and wire the Send Email node into any n8n workflow.
Per-node n8n execution debugging with Claude: patterns and pitfalls
Three silent n8n execution failures -- Filter node drops, missing AI Agent Chat Model, and inactive webhook -- plus how to use Claude and the n8n MCP to diagnose them in plain language.
How to fix n8n OAuth callback URL returning 401
Three causes of the n8n OAuth callback 401 and the exact fixes: WEBHOOK_URL mismatch, stale credentials after a domain change, and X (Twitter) OAuth1/OAuth2 endpoint confusion.
n8n Loop node only processes the first item: how to fix it
The Loop Over Items node only processes one batch when processing nodes aren't wired back to its input. Here's the exact fix, plus the Merge node pattern for conditional branches.
How to fix n8n webhook not firing (test URL vs production URL gotcha)
n8n has two webhook URLs: test (/webhook-test/) and production (/webhook/). Using the wrong one for your mode causes silent failures. Here is how to check which URL your integration is calling and how to fix it.
How to fix n8n webhook returning 403 instead of 401 for invalid Basic Auth
n8n returns 403 Forbidden (not 401) when Basic Auth credentials are wrong - breaking browser re-challenge flows. Three workarounds: nginx proxy, Header Auth, or the pending patch in PR #26402.