XF 1.5 No permission to upload attachment from Admin UI?

[Stockwalker]

I am trying to upload data to the attachments/do-upload endpoint with a POST request. From within the admin panel.

However, I get back this error:
You do not have permission to view this page or perform this action.

How may I fix this?

 

[Mike]

It likely means that you're not passing the correct data through or you're not logged in as you expect in the front end. The control panel and the front end are totally separate in terms of session management so trying to submit forms across them isn't really a recommended approach.