n8n error fixes

Plain-English explanations and step-by-step fixes for n8n agent errors.

• A Chat Model sub-node must be connected and enabled Your AI Agent has no 'brain' attached. An AI Agent node can't run on its own — it needs a language model (like an OpenAI or Anthropic chat model) plugged into it, and that model node has to be turned on.
• Authorization failed - please check your credentials The app your workflow talks to rejected the login n8n sent. The key or account is missing, typed wrong, expired, or not allowed to do this.
• Bad request - please check your parameters The app your workflow is talking to rejected the request because something in it was missing, misspelled, or in a format that app doesn't accept.
• Error: Failed to receive response The chat window sent your message to n8n but never got a usable reply back, usually because it can't reach n8n's address or the connection was cut.
• The requested webhook "[METHOD] [path]" is not registered. n8n received a call to your webhook URL but isn't currently listening on that address, so it returned a 404 (not found). Usually it means you used the test URL without first pressing the run button, or you used the test URL when you should be using the live one.
• The resource you are requesting could not be found The outside service your node is calling said 'I don't have anything at that address.' Something about the URL, the ID, or the request method is wrong, so the service can't find what you asked for.
• The service is receiving too many requests from you The app your workflow talks to got too many requests from you too fast, or your account hit its usage limit, so it's refusing more for now.
• Workflow could not be activated n8n tried to switch your workflow on, but its starting step (the trigger) couldn't connect to the service it listens to, so it isn't running.