Steps to reproduce:
1. Put some big (greater than 2GB in size) files in your inbox so that they get archived for uploading
2. Use the "Upload" menu and upload the files using the option "Designated inbox in server"
The pop-up dialog freezes in "Uploading catalog". Such catalog is uploaded immediately before the video files. Inspecting the HTTP transactions using Chrome's "developer tools" or Firebug shows that the video files are being "moved" (using the "files" endpoint), which is expected to take some time, but the dialog does not show any progress, so the operator may think the uploading is frozen.
The dialog should show the uploading progress as expected.