URGENT: Webhook POST returns “Cannot POST” on active workflows – No reply to ticket #7618625

Questions
1

Hello Everyone:
I’m building a fully autonomous AI system (SYNTARA) and needed to confirm whether n8n can generate and upload files to Google Drive automatically, using only API and system triggers, without any manual intervention.

The goal was for n8n to:

  1. Receive a text string and a file name from a webhook.
  2. Create a .txt file dynamically.
  3. Upload that file into a specific Drive folder.
  4. Confirm execution (optionally respond to webhook).

We hit several blockers with the fileName field not evaluating expressions like {{$binary.data.fileName}}, and webhook behaviors between Test URL vs Production URL.

What is the error message (if any)?

  • Cannot POST /webhook/subir-a-drive when trying to use Production URL from outside.
  • Files were uploaded with the literal name {{$binary.data.fileName}} instead of resolving the expression.
  • Some executions failed silently unless “Test Event” was actively listening.

Please share your workflow

json

CopiarEditar

Share the output returned by the last node

memoria_2025-05-02T06-22-11-123Z.txt was successfully uploaded to the correct Google Drive folder with full automation from webhook.

Information on your n8n setup

  • n8n version: 1.44.0
  • Database: Default (SQLite)
  • n8n EXECUTIONS_PROCESS setting: own
  • Running n8n via: VPS with Docker
  • Operating system: Ubuntu 22.04 LTS

Let me know if you’d like a cleaner export .json of the workflow or if this should be posted in “Showcase” instead of “Questions”. This is part of a larger self-writing, self-learning AI system and I’m happy to share progress.

2

Hey @Sistema_Syntara Welcome to the community.
Sharing your template would definitely help with figuring out what the exact issue is but here’s 2 ways to achieve what you’ve described.

If you’ve set the workflow to “active” and still experiencing production webhook URL access issues, it may be your server/DNS configuration.

3

Hi Jim_Le,

I just wanted to sincerely thank you for the advice and support you’ve shared recently. Your insight into n8n and MCP has been extremely helpful, and I really appreciate your willingness to contribute to the community.

To be completely honest, I’m not very experienced with n8n or this type of technical integration. I’ve been trying to build a working workflow that uses MCP (Model Context Protocol) to connect with Google Drive, allowing a language model to autonomously copy, upload, rename, and share files based on input parameters like fileId, copyName, and parentId.

Despite several attempts, I haven’t been able to get it working properly.

That’s why I wanted to kindly ask:
If you happen to have a fully functional workflow that accomplishes this, would you be open to sharing it—or even selling it? I completely understand if not, but I’d be more than happy to purchase it if that’s an option you’d consider.

Thank you again for your time and generosity. It means a lot!

Warm regards,
Richo

¿Quieres que lo firmemos con una frase extra tipo “I’m working on a broader AI system and your help would unlock the next step”?

4o

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