Sub workflow error: "Missing node to start execution - Please make sure the workflow you're calling contains an Execute Workflow Trigger node"

[Levente_Toth]

I have a self-hosted n8n v1.115.3 instance (Docker).

Everything was working perfectly — my AI agent used the Call Workflow (Execute Workflow) node to call another workflow called Event_Check.

Then, without any structural change to the workflows, the system suddenly started returning this error:

Missing node to start execution

Please make sure the workflow you’re calling contains an Execute Workflow Trigger node

Since then, the sub-workflow refuses to run.

It had been working fine for weeks with exactly the same setup.

Context

• Parent workflow: AI agent orchestration pipeline (triggered by webhook)

  → uses Call ‘Event_Check’ (Execute Workflow node) to fetch available appointment slots.

• Sub-workflow: Event_Check

  → starts with “When Executed by Another Workflow” trigger

  → collects calendar data and returns the formatted availability list.

• Expected behavior: The Execute Workflow node should call Event_Check, wait for completion, and receive the results.

• Actual behavior: It fails instantly with “Missing node to start execution”.

What I’ve checked

1. The Event_Check workflow definitely contains a valid Execute Workflow Trigger node, connected to the main branch.

2. Tried multiple n8n builds and versions — same issue everywhere.

3. Tried creating new minimal workflows:

   • Sub-workflow: Execute Workflow Trigger → Set(pong=true)

   • Parent workflow: Manual Trigger → Execute Workflow (call the above)

     → Still fails with the same error.

4. Both workflows are in the same Project.

5. Tried referencing by name and by ID — no difference.

6. Restarted and rebuilt Docker containers, cleared cache, re-imported workflows.

7. No code or schema changes inside Event_Check.

   The only unrelated change was to the AI agent’s system prompt, which does not affect this node.

Environment

• n8n version: 1.115.3

• Deployment: Self-hosted (Docker)

• Binary Data Mode: default

• Mode: Run once with all items

• Wait for completion: Enabled

• Source: Database

Observed result

Even though Event_Check starts with a valid “When Executed by Another Workflow” trigger, n8n refuses to execute it, reporting “Missing node to start execution”.

This happens across all versions tested and even with brand-new, minimal workflows.

Information on your n8n setup

• n8n version: 1.115.3
• Database (default: SQLite):
• n8n EXECUTIONS_PROCESS setting (default: own, main):
• Running n8n via (Docker, npm, n8n cloud, desktop app): Docker
• Operating system: MAC OS 15.6

[Parintele_Damaskin]

Simply remove the Call ‘Appointment dev’ final node in the subworkflow.

It will return anyway the response to the main workflow ai agent, together with the intermediateSteps(if you enabled it).

[Levente_Toth]

Hehe

Man you saved me a few mental breakdown

But now I dont understand why was it working for the last 3 weeks with that setup.

[Parintele_Damaskin]

glad that I could help you!

Maybe node versions with the new version update conflict I guess …

Mark the answer as solved , if it helped.