Error trying to run test server

I did everything in there https://github.com/n8n-io/n8n/blob/master/CONTRIBUTING.md to develop a custom node, when I run a npm run dev and get the url where the server is running and click on it I get the error on the image bellow

Me too :thinking:

did everything again and it worked! did not change anything. weird

Ah was just starting to look into it. All very strange. I never encountered that problem developing locally. Just know it when Nginx reverse proxy is used and not properly configured.

I restart my server and now everything is ok.

Great to hear that it also works for you now. At least we have an easy work around “restart” till we found the underlying problem.