I was having intermittent search failures this morning, but now every query results in this error:

    Sorry, we ran into an error displaying these results. Click here to try again.

I tried looking for an official status page, but couldn't find one. That said, it looks like others are having the same issue: https://downdetector.com/status/duckduckgo/

EDIT: They've now updated the search results page with the following after it returns no results:

    We’re experiencing an outage.
    Thanks for your patience while we get our ducks in a row!