"Unfinished Business" feels curiously off from the very beginning, and never manages to recover. A film of split personalities, it strives to be a low-key observational comedy, a raunchy, sex- and drug-filled farce, and a message drama about the evolution of bullying in a social media-infused world. The picture works best as the former, but the direction by Ken Scott (2013's "Delivery Man") and screenplay by Steve Conrad (2013's "The Secret Life of Walter Mitty") are pedestrian and lacking in flavor. As an R-rated goof, scenes involving creative bedroom play and trips to an all-nude unisex spa and a rowdy gay nightclub just sort of sit there, stretching for laughs without really having a viewpoint or reaching a payoff. And, as the story of a father who is struggling to raise his kids and help them through their problems while stuck in a different country, the picture awkwardly teaches its lessons as if it were taking place in an elementary school classroom.

Fed up with his workplace's restricting department salaries, Daniel Trunkman (Vince Vaughn) quits his job and vows to start his own business. A year later, he and his two faithful employees—ready-for-anything 67-year-old Timothy McWinters (Tom Wilkinson) and naïve, inexperienced twenty-something Mike Pancake (Dave Franco)—have seen little movement on wrangling clients. Just when it seems as if they will have to throw in the towel, an opportunity to close a lucrative deal sends the three guys on a business trip to Portland, Maine, and, later, Germany. Taking advantage of the "all-work-and-no-play" adage, Timothy sets out to let loose in between client meetings while Mike sees his virginity vanish while practicing a laborious sexual position called "The Wheelbarrow." As for the more responsible, married Daniel, he realizes this overseas trip will either make or break his company. Adding fuel to the fire is his main competition: his prickly former boss Chuck Portnoy (Sienna Miller).

The problem with "Unfinished Business" is not that it is outright terrible, but that it is so terminally bland. The story passes by in a haze of laid-back disposability, while the movie's randier side feels contrived, uninspired and sapped of energy. Situations that one expects to lead to a punchline of some sort—as when Mike has to take over a crucial presentation when Daniel falls ill—instead anticlimactically cut to the next scene with little fanfare. Adversarial characters like Chuck show up only for nothing of note to be done with them. Vince Vaughn (2013's "The Internship"), Tom Wilkinson (2014's "The Grand Budapest Hotel") and an especially charming Dave Franco (2014's "Neighbors") are solid in the lead roles, but let down by the tone-deaf confusion surrounding them. When "Unfinished Business" reaches its nice if sleepy little conclusion, the journey getting to this point would be remembered as a waste if it weren't so instantly forgettable.