He was last seen at about 10.55pm on August 3 in the city, but also has links to Horsham, Hassocks, Bognor and Worthing in West Sussex.
Tyler is tall with short brown hair and of stocky build. He was last seen wearing a grey tracksuit, black trainers and carrying a black backpack.
Anyone who sees Tyler or knows his whereabouts is asked to report it to Sussex Police be calling 101 quoting serial 158 of 04/08.