Unexpected Behavior When Using Merge Node to Join Different Types of WhatsApp Messages

[Kinterofoto]

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Issue: Unexpected Behavior When Using merge Node

Description

I’m experiencing unexpected behavior when using the merge node in my workflow. Here’s what’s happening:

• When I add the merge node, the workflow breaks.

• When I remove the merge node, everything runs perfectly.
  

  

• I use the merge node in other workflows without any issues, so this seems to be a specific case.

Context

To avoid generating a response for every message sent, I integrated Redis as a way to control flow or rate limit responses.

In this setup, I need to merge inputs before proceeding, which is why including the merge node is essential.

What I Need

Any suggestions or guidance on how to:

• Use the merge node properly in this scenario.
• Diagnose why it’s breaking the workflow in this specific case.

What is the error message (if any)?

Workflow execution had an error

Cannot read properties of undefined (reading ‘execute’)

Please share your workflow

(Select the nodes on your canvas and use the keyboard shortcuts CMD+C/CTRL+C and CMD+V/CTRL+V to copy and paste the workflow.)

Share the output returned by the last node

Information on your n8n setup

• n8n version: Version 1.90.2
• Database (default: SQLite):
• n8n EXECUTIONS_PROCESS setting (default: own, main):
• Running n8n via (Docker, npm, n8n cloud, desktop app): Railway template
• Operating system:

[Franz]

Based on how the workflow is set up, I’m not sure if you even need a Merge Node.

The Merge Node is mainly used when there are multiple paths in the workflow that are always executed. That’s why it has the Number of Inputs parameter, because the Merge Node waits until all the inputs are available.

If only one path is followed per execution because only one message is processed at a time, then a No Operation node or an empty Edit node with (Include Other Input Fields = true) will be enough.

[Kinterofoto]

I was needing the merge node, cause the redis node output can have several types of messages. But I already solve the proble changing the logic.