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 Draft 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.
• The requested webhook "[METHOD] [path]" is not registered. Click the 'Execute workflow' button on the canvas, then try again. (404 not found) Draft 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 (404) Draft 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.