I accidentally hit c with a card selected and archived the card. I tried to undo the archive but couldn't find the option. I tried moving the card back to the list but that didn't seem to work.


Question: No navigation links on 404 pages Drupal 7
Answer: There are also good module alternatives:


Search 404



  Instead of showing a standard "404 Page not found", this module performs a search on the keywords in the URL, e.g. if a user goes to http://example.com/does/not/exist, this module will do a search for "does not exist" and shows the result of the search instead of the 404 page. This should help retain visitors coming in from old URLs linked from other sites or from search indices.
  Fast 404



  Drupal has expensive 404 errors. On an 'average' site with an 'average' module load, you can be looking at 60-100MB of memory being consumed on your server to deliver a 404. Consider a page with a bad .gif link and a missing .css file. That page will generate 2 404s along with the actual load of the page. You are most likely looking at 180MB of memory to server that page rather than the 60MB it should take.