It’s a movie about marital dysfunction on a family ski trip. So, “Downhill,” get it? Directors Nat Faxon and Jim Rash, are the screenwriters of “The Descendants” and writer/directors of “The Way Way Back.” The key element that made those films remarkable was a blending of wry humor with heart-breaking family tensions and conflicts. But here, co-scripting with Jesse Armstrong (“In the Loop”), that is where it fails. Both elements are present, but the film and its performers never seem to know which part they are in.

Perhaps one problem is in the casting and marketing of the film, with two of the most beloved comic actors of all time creating an expectation that we are there to laugh at them. Will Ferrell and Julia Louis-Dreyfus are equally good in serious roles, but having them in a film that tries to make us laugh at their struggles and feel sympathetic to them or at least recognize something of ourselves in them is more than even the most adept performers can manage. It does not help that the trailer makes it seem like an outright comedy, so the audience arrives with expectations that make it difficult to locate the movie’s tone.

It is based on the Cannes-jury prize winning Swedish film “Force Majeure.” The name is a legal term meaning a supervening event that makes it impossible to fulfill a contract, like a catastrophic storm. In this version, it is an American family with two sons who arrive at an Austrian ski resort for a family vacation. Peter (Will Ferrell), is still mourning his father who died eight months earlier and is questioning his own life, whether he is missing something he might never find time to have or do. Billie (Julie Louis-Dreyfus) is a lawyer looking forward to quality family time and her husband’s undivided attention. The opening scene (also in the original) is reminiscent of “Ordinary People,” making clear the family’s inability to get together for a photograph, demonstrating the deepening divide between the way they want to appear and the way they are.

On their second day at the resort, a controlled avalanche on one of the mountains briefly looks as though it will cover the balcony cafe where the family is eating. In that split second, instead of protecting his family, Peter grabs his cell phone and runs for cover. Billie and the boys are badly shaken but say nothing at first. As the vacation continues, Billie’s feelings: abandonment, anger, contempt, bubble up, revealed in ways that range from passive aggressive to micro-aggressive to outright, pull out all the stops aggressive.

Louis-Dreyfus, who also produced, navigates this range of moods with extraordinary sensitivity as Billie struggles to do what is best for her sons’ sense of security and respect for their father and her fury, fear, and frustration with Peter first for his cowardly, selfish act and then for denying it and trying to blame her for talking about it. It all erupts into a painful and humiliating series of accusations and denials in front of Zach, one of Peter’s colleagues from work (Zach Woods) and his free-spirited new girlfriend (Zoe Chao). There is an intriguing idea there about what Peter hope to appear or be for Zach and why, but instead of exploring it we get Miranda Otto in the thankless role of a resort liaison whose job seems to be welcoming guests with the very definition of sexual TMI. The same goes for brief flirtations with flirtation by both Billie and Peter. Yes, middle-aged people sometimes wonder where their youth has gone and long to be seen as new and desirable. That point has been made much better many, many times.

Even with a brief running time and deft performances, the movie never settles on a tone or perspective.

Parents should know that this movie includes some peril and extended family dysfunction, tension, and arguments. There are very explicit sexual references and a situation and a reference to drugs.

Family discussion: Why did Billie want her sons to see Peter do something good? What would you do if you were faced with Peter’s decision? How do you know? Why was it hard for him to tell the truth?

If you like this, try: the original film, “Force Majeure” and “Carnage”