I've tried a few times to upload a map today, without success, despite having success in the past.
Step 1 - uploading the map appears to work as normal.
Step 2 - choosing the screenshot lets me upload one, but then the widget to crop the screenshot doesn't work properly (no big deal, screenshot not too important)
However, the world never goes into the queue to get rendered, and subsequent attempt to download the map just get an empty zip archive. I've tried uploading a new world, as well as updating an existing world's archive (with 'render again' selected), no dice. I even tried changing the world folder's name in case somehow that was screwing something up.
Any other diagnostics I can offer?