Michael Douglas (“Behind the Candelabra,” 2013) and Diane Keaton (“Something’s Gotta Give,” 2003) star in “And So It Goes,” the newest—possibly umpteenth—stab at a romantic comedy-drama by director Rob Reiner (“When Harry Met Sally,” 1989). Douglas plays Oren Little, a realtor who’s left in charge of his granddaughter Sarah (Sterling Jerins; “The Conjuring,” 2013) by his estranged son Luke (Scott Shepherd; “Side Effects,” 2013). Having shunned the world around him and unable to care for Sarah—who he’s never known before—he’s forced to ask his neighbor Leah (Keaton) for help.

The film starts with promise—a sweeping aerial shot of the neighborhood it’s set in plays out while Joni Mitchell croons the heartrending “Both Sides Now,” setting the tone for what could have been a laidback and comforting, if melancholic, drama. Unfortunately, Reiner sleepwalks his way through Mark Andrus’s (“As Good As It Gets,” 1997) trope-y screenwriting, completely undoing any goodwill set by the tone in the opening titles. Douglas is the cranky, jilted man with a dead wife, and Keaton’s the woman who could never have kids, finding a second chance at companionship in the process of taking care of this new child, who—it becomes painfully clear to viewers—ends up becoming the oldest MacGuffin in the book of drama MacGuffins.

Not that the film is insufferable; for all of its lifelessness, Reiner’s direction is reasonably competent. It’s also easy on the eyes, thanks to Reed Morano’s (“For Ellen,” 2012) cinematography, giving the film a quaint and cozy vibe. Reiner regular Marc Shaiman’s soundtrack isn’t groundbreaking but lends to the film’s overall intimate, old-world style. From the perspective of technical craft, nothing really seems out of place. None of it seems to help the frustratingly uninspired narrative, however, turning “And So It Goes” into a largely inoffensive but depressingly fruitless viewing experience.

None of this is on Douglas or Keaton, though. They’re both commendable and lend the film an air of quiet dignity, not because of the narrative but despite it. The former, in particular, is incredibly likable as the gruff, unlikable man and tries as much as he can to give his Ebenezer-Scrooge-esque personality some genuine pathos. Keaton, unfortunately, gets the shorter end of the stick here, with every stereotype you can think of thrown at her. While—in most of the film—it does appear that she phones in her performance, it’s also primarily due to the absurdly one-dimensional character trope she’s forced to sleepwalk through.

While you won’t necessarily walk out in the middle of the movie, Reiner’s “And So It Goes,” at the end of the day, wastes its phenomenal talent in front of the camera on a film where nothing that’s even remotely emotionally compelling happens throughout its narrative. Disappointing.