'Please select a file' when attempting to upload or replace from the UI

What

Clicking upload does nothing the first time and produces a dialog the second time. It then uploads on without further interaction anyway.

Steps to reproduce

1. Click +, followed by Upload file
2. Choose a file with the file picker dialog
3. Attempt to press upload, possibly before the upload has finished
4. Nothing happens
5. Press again
6. Dialog appears

Screenshot