Form end page not working in multi-step form (completion)

[adrian-martinez-onestic]

Bug Description

In a multi-step form, after completing first and second steps, form end page is not shown (at least when configured as Show completion screen); it fails and shows the following message: {"code":0,"message":"Workflow Form Error: Workflow could not be started!"}.

It does not work neither in test or production modes, execution fails with the following error:

Cannot read properties of undefined (reading 'redirectUrl')

Details:

{
  "errorMessage": "Cannot read properties of undefined (reading 'redirectUrl')",
  "errorDetails": {},
  "n8nDetails": {
    "n8nVersion": "1.73.1 (Self Hosted)",
    "binaryDataMode": "filesystem",
    "stackTrace": [
      "TypeError: Cannot read properties of undefined (reading 'redirectUrl')",
      "    at Form.webhook (/usr/local/lib/node_modules/n8n/node_modules/.pnpm/n8n-nodes-base@file+packages+nodes-base_@[email protected]_@aws-sdk+credential-provi_b5z6rj2bs5tsb6yffsyzoevhmy/node_modules/n8n-nodes-base/dist/nodes/Form/Form.node.js:240:24)",
      "    at WebhookService.runWebhook (/usr/local/lib/node_modules/n8n/dist/webhooks/webhook.service.js:181:30)",
      "    at Object.executeWebhook (/usr/local/lib/node_modules/n8n/dist/webhooks/webhook-helpers.js:156:96)",
      "    at processTicksAndRejections (node:internal/process/task_queues:95:5)"
    ]
  }
}

It's worth noting that disabling the intermediate step makes it to work properly, it seems some edge case is not properly covered in form ending case.

To Reproduce

Create a workflow based on these nodes, and execute it in test or production mode:

{
  "nodes": [
    {
      "parameters": {
        "formTitle": "Test form",
        "formDescription": "Form description",
        "formFields": {
          "values": [
            {
              "fieldLabel": "Type a number",
              "fieldType": "number",
              "placeholder": "8",
              "requiredField": true
            }
          ]
        },
        "options": {}
      },
      "type": "n8n-nodes-base.formTrigger",
      "typeVersion": 2.2,
      "position": [
        -260,
        -120
      ],
      "id": "cf8e7744-878a-43ff-b7ca-14f891c8fa2e",
      "name": "On form submission",
      "webhookId": "a1f954e9-6d49-4a4b-8a31-829132384697"
    },
    {
      "parameters": {
        "formFields": {
          "values": [
            {
              "fieldLabel": "Type a letter",
              "placeholder": "C",
              "requiredField": true
            }
          ]
        },
        "options": {}
      },
      "type": "n8n-nodes-base.form",
      "typeVersion": 1,
      "position": [
        -40,
        -120
      ],
      "id": "d243caad-6309-45cb-82cd-471e3d289042",
      "name": "Form",
      "webhookId": "0efe4d7a-c785-475b-9beb-cb9b26bdc215"
    },
    {
      "parameters": {
        "operation": "completion",
        "completionTitle": "OK",
        "completionMessage": "OK message",
        "options": {
          "formTitle": "Completion page title"
        }
      },
      "type": "n8n-nodes-base.form",
      "typeVersion": 1,
      "position": [
        180,
        -120
      ],
      "id": "d3dd9f75-5013-4265-8752-2f578108a449",
      "name": "Form ending",
      "webhookId": "26c54a69-c0d0-4f47-89c4-3870bf7f2256"
    }
  ],
  "connections": {
    "On form submission": {
      "main": [
        [
          {
            "node": "Form",
            "type": "main",
            "index": 0
          }
        ]
      ]
    },
    "Form": {
      "main": [
        [
          {
            "node": "Form ending",
            "type": "main",
            "index": 0
          }
        ]
      ]
    }
  },
  "pinData": {}
}

Expected behavior

The same as if the intermediate step wasn't there or disabled: show the completion page.

Operating System

Docker on Linux

n8n Version

1.73.1

Node.js Version

The version that 1.73.1 uses

Database

PostgreSQL

Execution mode

queue

[Joffcom]

Hey @adrian-martinez-onestic,

We have created an internal ticket to look into this which we will be tracking as "N8N-8035"

[Joffcom]

Hey @adrian-martinez-onestic,

Ignore the tracking ticket above, This was reported internally last week and we have an id of NODE-2187 for that which we will use for this as well.