When I click on the upload arrow near my skin in the skin browser the "Want to upload x to workshop" dialog pops up. However, when I click on Upload, the dialog closes and nothing happens.

I've uploaded one skin in the past, and didn't have that problem. However, this time around I've tried to cut down on the excess files in my skin, by only including the files I call in my skin.lua. I also have uigraphic.jpg, uigraphic_big.jpg, and workshop_image_640x360.jpg.

Are there any files that are required for upload, but the skin will run errorless without? Or is uploading just broken right now?