Homeboy Matt Damon will have to ratchet up the hype machine if he has any hope of countering critics of his new movie, “Monuments Men.” Directed by George Clooney, the film about a WWII platoon charged with rescuing art masterpieces from Nazi thieves is getting mostly negative reviews, and that doesn’t bode well for the box office. (Variety’s Scott Foundas called the film “exceedingly dull and dreary,” and Indiewire’s Drew Taylor said it’s “an unwieldy, overtly sentimental (but still emotionally distant) epic.” Damon’s salvage mission starts Monday with a panel discussion at Harvard’s JFK School. The actor will be there via Skype with Robert Edsel, who wrote the book on which the movie is based. The film is of local interest because Clooney’s character, George Stout, was a conservator at Harvard’s Fogg Museum and later became director of the Worcester Art Museum and the Gardner Museum. In addition to Clooney and Damon, “Monuments Men” stars Bill Murray, Cate Blanchett, and John Goodman. It opens Feb. 7.