Node does not wait for predecessor node - always need a Merge Node?

[Tobi]

I have this workflow.

I make two parallel calculations.

1. I calculate the tax
2. I transform the data for listing the products on the invoice

The response node is intended to summarize the results of the two calculations. The problem is that the response is not waiting for the second calculation to be completed. I got this error in the node

NodeOperationError: Referenced node is unexecuted at Object.execute

Working example
If I add a merge node, it works.

I’m just wondering why I always have to use a merge node to wait until all branches are completed to continue execution. It should be clear from the sequence that you have to wait until all the nodes have been executed.

That is not yet so clear to me

[n8n]

It looks like your topic is missing some important information. Could you provide the following if applicable.

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

[gualter]

hi @Tobi

Welcome to the community! I had some doubts around node execution order as well in the past but they have it documented here: Execution order in multi-branch workflows | n8n Docs

The advanced video course also speaks about this execution order with some examples: n8n Advanced Course (1/8) - Working with complex data flows

Hope this helps!