The read file node acts in a strange way. Can't resolve it

Alex_Satya · December 17, 2025, 10:58pm

Describe the problem/error/question

In using the read file node the node returns a valid file but I cannot download it using the button + the next nodes get a 9 byte empty file instead of the actual file.
Now I checked via FTP and I know for a fact that the file is indeed in place in the correct folder and have manually downloaded it to make sure that it is indeed a good video file with no issues.
Just to be clear it worked just fine a few hours ago I didn’t change any config files/compose data nothing. The node just stopped working.

What is the error message (if any)?

This is how the file is read

When trying to click download chrome says:

Please share your workflow

Doesn't seem to be relevant here I am just trying to read a file that is on the disk.

Share the output returned by the last node

When trying to upload the file:

Information on your n8n setup

n8n version: 2.0.3
Database (default: SQLite): postgresql
n8n EXECUTIONS_PROCESS setting (default: own, main): default
Running n8n via (Docker, npm, n8n cloud, desktop app): docker
Operating system:ubuntu 22.04

mohamed3nan · December 18, 2025, 2:26am

Hi @Alex_Satya,

I have the same issue and reported it about a month ago but still haven’t got a reply from the team,
However it seems to be a bug since the issue has been assigned to a team..

github.com/n8n-io/n8n

Incorrect MIME Type when reading file using “Read/Write Files from Disk” node

opened 03:26PM - 18 Nov 25 UTC

Mohamed3nan

team:nodes triage:complete status:in-linear status:team-assigned status:pending-assignment

### Bug Description Hello,, After updating n8n to the beta version, the `Read/…Write Files from Disk` node returns a different MIME type than in the previous version (1.120.3). In the previous version, an MP4 file written using the same node would later be read with the MIME type: `video/mp4` After upgrading, reading the exact same MP4 file now returns: `application/mp4` <img width="1514" height="540" alt="Image" src="https://github.com/user-attachments/assets/9dae38bd-ca2d-44bd-bf54-272a58c3ceea" /> ### To Reproduce 1. Create a workflow that writes a .mp4 file using the Read/Write Files from Disk node. 2. Read the same .mp4 file using the same node. 3. Inspect the binary metadata returned. Workflow to Reproduce: ```json { "nodes": [ { "parameters": { "operation": "write", "fileName": "/n8n_data/output.mp4", "dataPropertyName": "data0", "options": {} }, "type": "n8n-nodes-base.readWriteFile", "typeVersion": 1, "position": [ 656, 208 ], "id": "1786827e-1a17-4273-8c14-c0f6480e06a2", "name": "Read/Write Files from Disk1" }, { "parameters": { "options": { "allowFileUploads": true } }, "type": "@n8n/n8n-nodes-langchain.chatTrigger", "typeVersion": 1.4, "position": [ 432, 208 ], "id": "c6548e10-5d69-4019-9ae4-542003e532f3", "name": "When chat message received", "webhookId": "b473a745-8d04-4d83-bb7d-79a07edf99b2" }, { "parameters": { "fileSelector": "/n8n_data/output.mp4", "options": {} }, "type": "n8n-nodes-base.readWriteFile", "typeVersion": 1, "position": [ 912, 208 ], "id": "f2d42429-4a62-4d0a-bdbb-5aec3ee5526a", "name": "Read/Write Files from Disk" } ], "connections": { "Read/Write Files from Disk1": { "main": [ [ { "node": "Read/Write Files from Disk", "type": "main", "index": 0 } ] ] }, "When chat message received": { "main": [ [ { "node": "Read/Write Files from Disk1", "type": "main", "index": 0 } ] ] } }, "pinData": { "Read/Write Files from Disk1": [ { "sessionId": "372fba937523464085366d881565fd29", "action": "sendMessage", "chatInput": "ee", "files": [ { "fileName": "output.mp4", "fileSize": "805267 bytes", "fileExtension": "mp4", "fileType": "video", "mimeType": "video/mp4" } ], "fileName": "/n8n_data/output.mp4" } ], "When chat message received": [ { "sessionId": "372fba937523464085366d881565fd29", "action": "sendMessage", "chatInput": "ee", "files": [ { "fileName": "output.mp4", "fileSize": "805267 bytes", "fileExtension": "mp4", "fileType": "video", "mimeType": "video/mp4" } ] } ], "Read/Write Files from Disk": [ { "mimeType": "application/mp4", "fileName": "output.mp4", "fileExtension": "mp4", "fileSize": "805 kB" } ] }, "meta": { "templateCredsSetupCompleted": true, "instanceId": "4ae195bf9aee1a545632cb1a7b5f0d73fa1ec648553b781b97113639d10a41bf" } } ``` ### Expected behavior The node should preserve or correctly detect the MIME type and continue to return: `video/mp4` instead of: `application/mp4` ### Debug Info # Debug info ## core - n8nVersion: 1.121.0 - platform: docker (self-hosted) - nodeJsVersion: 22.21.0 - nodeEnv: production - database: postgres - executionMode: regular - concurrency: -1 - license: enterprise (production) - consumerId: c7e31770-5ee2-46d8-a026-527286c836c1 ## storage - success: all - error: all - progress: false - manual: true - binaryMode: memory ## pruning - enabled: true - maxAge: 336 hours - maxCount: 10000 executions ## client - userAgent: mozilla/5.0 (windows nt 10.0; win64; x64) applewebkit/537.36 (khtml, like gecko) chrome/142.0.0.0 safari/537.36 - isTouchDevice: false Generated at: 2025-11-18T15:18:23.035Z ### Operating System Ubuntu ### n8n Version 1.121.0 ### Node.js Version 22.21.0 ### Database PostgreSQL ### Execution mode main (default) ### Hosting self hosted

There are some workarounds mentioned on GitHub..

In short for now, you need to manually set the MIME type from application/mp4 to video/mp4

Hope this helps..

Alex_Satya · December 18, 2025, 6:44am

On the one hand good to hear that it is assigned. On the other hand the solution did not work for me the file still doesn’t open.

Thank you for updating

Alex_Satya · December 18, 2025, 8:53am

For the time being as strange as it sounds I ended up using execute node with curl to upload a file…