It should be possible by using the Attachments tab. Attach your file to the PUT request and make sure the Media type is multipart/form-data or multipart/mixed.
With the size of your file you probably would not want to cache it in the project to avoid its size increase.
This looks like a bug in Ready! API, please contact our support team.
We will most likely need your project and attachment to reproduce it locally and find what causes the error.
There might be a workaround with Groovy scripts, but using Attachments is the recommended method.
