Problem sending Binary Data with "Respond to Webhook"

[fjodorsch]

Bug Description

Sometimes,
When responding with large Binary Data (> ca. 2 MB) with the "Respond to Webhook" Node
the following Error is logged to the n8n console.

Error: Cannot set headers after they are sent to the client
    at new NodeError (node:internal/errors:405:5)
    at ServerResponse.setHeader (node:_http_outgoing:648:11)
    at ServerResponse.header (/usr/local/lib/node_modules/n8n/node_modules/express/lib/response.js:795:10)
    at ServerResponse.send (/usr/local/lib/node_modules/n8n/node_modules/express/lib/response.js:175:12)
    at ServerResponse.json (/usr/local/lib/node_modules/n8n/node_modules/express/lib/response.js:279:15)
    at Object.sendSuccessResponse (/usr/local/lib/node_modules/n8n/dist/ResponseHelper.js:28:17)
    at /usr/local/lib/node_modules/n8n/dist/WebhookHelpers.js:114:24
    at processTicksAndRejections (node:internal/process/task_queues:95:5)
Error: Premature close
Error with Webhook-Response for execution "3019974": "Premature close"

And if the File were an Image for example it would only load like half way.
Chrome logs:

Failed to load resource: net::ERR_HTTP2_PROTOCOL_ERROR

Workaround:

In the Webhook node, use

• Respond
  • When Last Node Finishes
• Response Data
  • First Entry Binary

To Reproduce

Workflow to showcase:

Test.json

Expected behavior

work

Operating System

Official Docker Image running on Ubuntu

n8n Version

1.38.2

Node.js Version

18.19.1

Database

PostgreSQL

Execution mode

main (default)

[netroy]

This is likely the same issue we've been trying to fix in #9063.

I've just created a new docker image n8nio/n8n:fix-9291 from that branch.
Can you try switching to this docker image to see if it fixes the issue for you?

[fjodorsch]

Ok, I tested it with the Image n8nio/n8n:fix-9291 on my laptop using the same workflow and
it works.

Edit: Only because I didn't use - N8N_DEFAULT_BINARY_DATA_MODE=filesystem

[fjodorsch]

Wait, I tested it again but with

- N8N_DEFAULT_BINARY_DATA_MODE=filesystem

and it happened again

[netroy]

We fixed a race-condition, and we have published a new docker image on the same tag n8nio/n8n:fix-9291.
Can you please pull the docker image again, and check if the issue is resolved for you 🙏🏽 ?

[netroy]

#9063 is merged and will be included in the next release tomorrow.

[janober]

Fix got released with [email protected]