TORONTO — Legiters are trying one more time for a successful stage version of “Gone with the Wind”: The 2012-13 season at the Royal Manitoba Theater Center, Canada’s largest and oldest regional, includes the world preem of Winnipeg playwright Niki Landau’s new adaptation of Margaret Mitchell’s Civil War tale.Whereas Landau’s version is a play, all other notable legit efforts at adapting the title have been tuners. Broadway regular John Lee Beatty will design the sets of the new Manitoba version, set to open Jan. 10. First of the prior failures was “Scarlett,” written by Harold Rome, which proved a hit when it opened in Tokyo in 1970 but didn’t conjure the same box office magic when the show, retitled “Gone with the Wind,” hit the West End in 1972. An American version folded on the road in 1973. A separate musical adaptation, helmed by Trevor Nunn and written by Margaret Martin, eked out a 79-perf West End run in 2008 after earning negative reviews. Other major shows in the RMTC season include a revival of Aaron Sorkin’s “A Few Good Men” and the hit Toronto production of “Assassins,” to be presented as the signature piece of a city-wide festival of composer-lyricist Stephen Sondheim’s work.