Tus: On upload error response is undefined

Initial checklist

• I understand this is a bug report and questions should be posted in the Community Forum
• I searched issues and couldn’t find anything (or linked relevant results below)

Link to runnable example

No response

Steps to reproduce

Hi,

I'm using Uppy Tus and with API returning 403 with:

{
    "message": "File cannot be uploaded as the BIN content type is disallowed!",
    "status_code": 403,
    "time_stamp": "2026-05-11T06:55:00.325+0000"
}

Nothing unusual, the screenshots below are self explanatory.

Expected behavior

We should be able to get the response message.

Actual behavior

The upload-error event and the complete , both have the response undefined, as you can see from screenshot. And the error message is built based on more strings which basically makes impossible to be used/decoded.

The Error object is constructed ok, based on the network response, but in resetUploadReferences call, the response is nulled/lost.