4.20.4: File upload is empty and request body is '[object object]'

[gregg-cbs]

Bug report

Required System information

• Node.js version: 18.6.0
• NPM version: 9
• Strapi version: 4.20.4

Describe the bug

In strapi 4.20.4 ctx.request.files is an empty object. In strapi 4.15.0 file upload to controllers were working fine. Since upgrading it is now broken.

Steps to reproduce the behavior

1. Send a multipart form data to a controller
2. Notice ctx.request.files is empty object
3. Notice ctx.request.body.files is '[object object]'

Expected behavior

File to be attached to ctx.request.files as it was in 4.15.0 and as Koa recommends.

Screenshots

Frontend Request (tried with file and files as the property name)

Controller header which shows file incoming:

Controller context request string object and empty files:

[gregg-cbs]

This is affecting my production site and I am panicked as to what to do here. File uploads is a big part of our product. If we downgrade back to 4.15.0 we then face the "internal server error" issue mentioned in this ticket #19686

[strapi-bot]

This issue has been mentioned on Strapi Community Forum. There might be relevant details there:

https://forum.strapi.io/t/file-upload-to-customer-controller-stopped-working-in-4-20-4/36629/10

[gregg-cbs]

Embarrassingly so this was an issue one of our developers introduced by changing our form on the front end. This is not an issue in strapi.