When Robin Williams playing a Catholic priest is the most restrained, subtle thing in a new slapstick farce masquerading as a rom-com family drama, there's a problem. And it's the least of dozens in Justin Zackham's new all-star adaptation of the little-seen French froth, Mon Frere se Marie, The Big Wedding. Although the trailers and the marketing campaign trot out Diane Keaton and Robert DeNiro and Susan Sarandon in sets that look like the next It's Complicated or Something's Gotta Give, there's no trace of the late Nora Ephron or Nancy Meyers to be found in this dull and witless affair. While those two might not be known as auteurs, both have spent years delivering exactly the goods a certain demographic wants: brand-name actors conflicted by impeccably lit high class problems for the 40-something set, pleasantly resolved in 90 to 100 minutes. The Big Wedding only gets the art direction and the lighting right. Rather than Father of the Bride or even Meet the Fockers, what is served up is far more akin to Dinner for Schmucks (another ill-advised adaptation from the French, and 2010's second-worst movie of the year.) The movie centers around the eponymous nuptial weekend of Missy (Amanda Seyfreid) and Alejandro (British actor Ben Barnes) at the family compound of Ben's adopted dad, Don (Robert DeNiro) and Don's longtime live-in girlfriend Bebe (Susan Sarandon), who broke up his marriage with family matriarch Ellie (Diane Keaton) years before. Along for the ride are the siblings Ben was raised with, Topher Grace as the 30-year-old virgin Jared, and Katherine Heigl as the angry and reproductively challenged eldest daughter, Lyla. (She's angry because "you didn't just divorce Mom!" although it takes a while to get to that point.) The paper-thin contrivance around which the movie is constructed: Alejandro's birth mother, Madonna, will be traveling to the wedding from Colombia, where... they don't believe in Divorce. Hence, Bebe must get the boot for the weekend, and Ellie and Don must pretend to still be married. Potentially, this could be a hilarious triangle of DeNiro and Keaton and Sarandon, but it isn't. Madonna also brings along Alejandro's sister (half sister?) Nuria, who exists for random nudity and as a Wedding Crashers plot device for poor Topher Grace. The movie attempts to satirize racism -- Missy's parents don't really want to be seen with their prospective "brown" son-in-law at their club -- but since Alejandro is played by a white British actor with an American accent, who isn't even a little bit tan, the jokes about the in-laws are mystifying at best. The in-laws are told they'll have to face the fact "you're gonna have bilingual beige grandchildren!" and it makes absolutely no sense. Alejandro's Mom gave him up for adoption to give him a "better life," but no mention is made of why she raised a daughter, his sister. Did she not deserve a "better life?" Every single aspect of this movie is lost in translation. DeNiro references his alcoholic past with expressions like "I drank my face off." A hint of the fact that we're meant to be watching a farce comes with gestures like Madonna standing in a doorway fingering her rosary and camping it up, but the dialogue isn't broad enough to play like a La Cage Aux Folles. DeNiro seems to have wandered over from the set of Silver Linings Playbook when he plays other lines earnestly like, "I couldn't stand being ignored." Diane Keaton and Susan Sarandon have great chemistry in the few scenes they have together, but the idea that best friends could be plausibly forgiving enough to sexually trade a husband back and forth is a French, or at least European, precept. Despite their best efforts, their scenes together make no sense, as written, in an American movie. Alcoholism as a silly plot contrivance might play fine in French farce, but Dan falling off the wagon for laughs is spectacularly tone deaf in "family drama" here. There might have been a movie in here somewhere -- what happens when blended families reunite? how is that first generation of the children of divorce-era holding up? what happens when lip service liberals tangle with country club racists? It could all still center around a wedding and be funny and raunchy and R-rated. Wedding Crashers and Bridesmaids certainly managed to do all three. This isn't that movie. This is just Weddings With Schmucks.