Unless you have client access to their API, URL shortener tr.im is no longer shortening URLs:
tr.im is no longer accepting URL shortening requests via its website. May we respectfully suggest that you choose one of the many other wonderful alternatives available.
Please understand that this does not affect any software that has tr.im available within it. tr.im’s API is available, and redirections are working normally.
TweetDeck used to support tr.im, but dropped it after the alleged coronation of bit.ly as the Sort of Official URL Shortener of Twitter.