If I add a new list in the UI, it disappears after a few seconds, and the browser console shows it got a callback reject and a 500 error.
If I add it with the API using python trello client, I get:
File "/usr/local/lib/python2.7/dist-packages/trello/trelloclient.py", line 210, in fetch_json
raise ResourceUnavailable("%s at %s" % (response.text, url), response)
trello.exceptions.ResourceUnavailable: Internal Server Error at https://api.trello.com/1/lists (HTTP status: 500)
Sorry if this is the wrong place to report it, but the Trello Status website doesn't have any "report issues" links, and it keeps saying nothing is wrong, which makes me worry they aren't properly monitoring their software stack and haven't been paged by this severe outage. Maybe someone knows how to pass it along.