Even the very best film-makers can lay an egg sometimes. And Ira Sachs has laid one so big that the walls of the Palais des Festivals may have be knocked down so it can be safely removed. This really is baffling, considering how superb his other movies have been, such as his complex drama Little Men (2016) and the wonderful lifelong-romance story Love Is Strange (2014).

But this is a blank, uneasy, pointless, variably acted multinational production, inertly set in the picturesque Portuguese city of Sintra – which is shot handsomely enough but with no special flair. Frankie looks like nothing so much as one of those late Woody Allen movies in a luxury tourist setting, only with even less possibility – in fact none at all – of any laughs. And no possibility of anything substantially serious, either.

Isabelle Huppert stars, gliding across the surface of the movie, doing a professional job and nothing more: her tendency to opaque hauteur is on show. She plays Françoise, or Frankie, a film and TV star who is treating her extended family to a sumptuous holiday so she can tell them something. They include her second husband Jimmy (Brendan Gleeson), her troubled son, Paul (Jérémie Renier), and equally troubled daughter Sylvia (Vinette Robinson). She has also invited her smart, pretty friend Irene (Marisa Tomei), who works in the film industry and whom she is hoping to pair off with unmarried Paul. But to Frankie’s chagrin, Irene has brought along her semi-serious boyfriend Gary (Greg Kinnear), and to Irene’s chagrin, Gary chooses this moment to make a kind of passive-aggressive marriage proposal, or at any rate move-in-to-save-money proposal.

This might well have made an intriguing and involving drama – a midsummer’s night’s comedy of family dysfunction – but the lines of dialogue fill the actors’ mouths like damp cotton wool as they stand around on the lovely picturesque streets like tailor’s dummies. The scenes have no fire or lightness and sometimes they are embarrassing. The very worst moment comes when Frankie broods over a flashy piece of jewellery, a diamond-and-gold bangle that an old lover gave her – it is worth thousands of Euros and she tries giving it to Paul to help him out with his money worries. Spoilt, petulant Paul throws this bangle into the undergrowth. After a brief exclamation of disgust at his foolishness, she starts looking for the thing but after a while gives up, laughing merrily, presumably at the absurdity of money and possessions. And that’s the last we hear of the bangle.

Even if we assume the darker moments of the plot explain this kind of supercilious casualness, we simply are not offered any satisfying and involving access to the characters’ lives, and certainly not to Frankie’s life. We don’t see any believable vulnerability or emotion, and Huppert is frankly not well managed or perhaps even particularly well cast in this role. The final shot is almost unbearably self-aware and yet redundant. Sachs is such a talented film-maker, but this is a baffling misstep.