Hi,
Any news on this?
I found a way of circumventing the issue by making 2 simultaneous calls to the API.
In call #1 POST /1.1/account/update_profile_background_image.json?use=false HTTP/1.1
In call #2 POST /1.1/account/update_profile_background_image.json?use=true HTTP/1.1
In call #1 image gets upload successfully (profile_background_image_url is set wit an URI to uploaded image) and in call #2 we make previously uploaded image active.
Like that I can successfully change the background image per API as we intend.
Can we make the assumption that this is going to work, for the time being?