Mason was originally sentenced in October 2015 for robbery and was released on licence in May 2018.
He is now wanted for recall to prison after breaching the licence conditions .
Anyone who thinks they might have seen Mason, or who has any information about his whereabouts, is asked to contact North Yorkshire Police.
Dial 101, press 1 and pass information on to the Force Control Room.
Alternatively, Crimestoppers can be contacted anonymously on 0800 555 111.