I'm getting a "Not Found" error when connecting a self-hosted n8n instance on Render.com to Google Cloud

[Ilias_Konstantopoulo]

Hello,
I am running a self-hosted n8n instance on Render.com and am having trouble with my Google Cloud credentials. I have already gone through extensive troubleshooting and have confirmed all my settings.
I am getting a “Not Found” error after successfully signing in to my Google account.
Here is my setup:
Hosting Platform: Render.com (on a paid plan with a persistent disk)
n8n Public URL: https://n8n-self-host-qmce.onrender.com
Environment Variable: WEBHOOK_URL is set to https://n8n-self-host-qmce.onrender.com/
This is the error I get:
Error Type: “Not Found”
Redirect URL: https://n8n-self-host-qmce.onrender.com/rest/oauth2-credential/callback
The redirect from Google is working, but n8n is not finding the callback path. Could you please help me diagnose why the n8n server is not handling this route correctly?
Thank you.

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[swoonunits]

Hello Ilias , the same Not Found error can be reproduced by visiting an invalid page such as

https://i-am-an-invalid-page.onrender.com

sound like either a failed deploy or another issue on Render.

Please follow the Deploy on Render documentation on deploying n8n and possibly contact them for support.

Deploy n8n on Render

[amohakam]

I am running N8N locally self hosted, but I learnt painfully that the call back URL is formed using both the N8N_HOST and N8N_PROTOCOL environment variables once I updated my DNS entries instead of localhost. My call back URLs work well in this environment.

In the second deployment, where I am setting this up locally with Cloudflare, I am having painful learnings around forwarding of traffic from the public internet, to my DNS provider to Cloudflare tunnel, to cloud flare agent and then finally to the docker container. I learn that that there is fire wall table rule that are blocking traffic from the Cloudflare agent to the docker. I am still debugging this.

All of that to say, have you checked whether there are any firewall end points that maybe preventing the call back through the routes your traffic takes.