Troubleshooting N8n ZIP File Decompression Issues On Windows

Hey guys! Ever run into a snag where you just can't decompress a ZIP file using n8n forms on Windows? It's a head-scratcher, right? This guide is all about tackling that issue head-on. We're diving deep into a specific bug report, breaking down the problem, and offering some seriously helpful solutions. So, if you're struggling with this, you're in the right place. Let's get those files unzipped!

Understanding the Issue

In the n8n community, a user reported a perplexing problem. When downloading a ZIP archive via an HTTP request in n8n, everything works like a charm. But, the moment the same archive is uploaded through a form, the decompression process fails. It’s like the file is playing hide-and-seek with the decompressor! This issue seems to pop up specifically on Windows systems with n8n deployed locally, adding another layer to the mystery. Let's break down the situation with some key points:

• HTTP Request vs. Form Upload: The core issue is the difference in behavior between downloading a ZIP file via HTTP request and uploading it via a form. The former works perfectly, while the latter results in decompression failure.
• Windows-Specific: This problem appears to be isolated to Windows environments where n8n is running locally. This narrows down the potential causes and suggests a possible operating system-related issue.
• Decompression Failure: The primary symptom is the inability to decompress the uploaded ZIP file. This indicates a problem with how the file is being handled or processed after the upload.
• Workarounds Exist: The user has discovered temporary solutions, which we'll delve into later. However, a permanent fix is desired for a smoother, more reliable workflow. Understanding these nuances is crucial for diagnosing and resolving the issue effectively. Let's dig deeper into the reproduction steps to get a clearer picture.

Reproducing the Bug: A Step-by-Step Guide

To really get to the bottom of this, we need to be able to reproduce the bug consistently. Here’s a breakdown of the steps, along with the n8n workflow code that highlights where the issue crops up. If you are facing issues with decompressing ZIP files, try reproducing these steps.

The n8n workflow provided includes nodes for:

• Manual Trigger
• HTTP Request
• Form Trigger
• Compression

The workflow is designed to demonstrate the difference in behavior between handling ZIP files downloaded via HTTP and those uploaded through a form. Here’s the JSON code snippet where the problem surfaces:

{
  "nodes": [
    {
      "parameters": {},
      "name": "On clicking 'execute'",
      "type": "n8n-nodes-base.manualTrigger",
      "position": [
        368,
        464
      ],
      "typeVersion": 1,
      "id": "2d5106a4-f22b-43aa-8cf9-1a8cbee63e16",
      "disabled": true
    },
    {
      "parameters": {},
      "type": "n8n-nodes-base.compression",
      "typeVersion": 1.1,
      "position": [
        768,
        240
      ],
      "id": "aaaf369b-287f-4cdc-9396-19e5065e6266",
      "name": "Compression"
    },
    {
      "parameters": {
        "url": "https://www.learningcontainer.com/wp-content/uploads/2020/05/sample-zip-file.zip",
        "options": {}
      },
      "id": "8b35e81a-05be-497e-b90d-fc8ac577e3f0",
      "name": "HTTP Request1",
      "type": "n8n-nodes-base.httpRequest",
      "typeVersion": 4.2,
      "position": [
        608,
        464
      ]
    },
    {
      "parameters": {
        "formTitle": "UPLOAD FILE",
        "formDescription": "UPLOAD FILE",
        "formFields": {
          "values": [
            {
              "fieldLabel": "data",
              "fieldType": "file",
              "multipleFiles": false
            }
          ]
        },
        "options": {}
      },
      "type": "n8n-nodes-base.formTrigger",
      "typeVersion": 2.2,
      "position": [
        368,
        240
      ],
      "id": "b02265b3-fe6d-481d-8571-bb7b5c4cc618",
      "name": "On form submission",
      "webhookId": "e76d2932-eaab-40f7-9cd5-7f742bd9ee35"
    }
  ],
  "connections": {
    "On clicking 'execute'": {
      "main": [
        [
          {
            "node": "HTTP Request1",
            "type": "main",
            "index": 0
          }
        ]
      ]
    },
    "HTTP Request1": {
      "main": [
        [
          {
            "node": "Compression",
            "type": "main",
            "index": 0
          }
        ]
      ]
    },
    "On form submission": {
      "main": [
        [
          {
            "node": "Compression",
            "type": "main",
            "index": 0
          }
        ]
      ]
    }
  },
  "pinData": {},
  "meta": {
    "instanceId": "bab56bc3b1fe17701f059dbb02dd7d3eb824b47c71e8ae5e9549347ab1f1ad2f"
    }
}

Steps to Reproduce

1. Set up n8n locally on a Windows machine.
2. Import the workflow provided in the JSON code above.
3. Trigger the workflow in two ways:
   • Using the