Emma Mackey in Stale James L. Brooks Comedy

Let’s not beat around the bush. I possibly speak for most critics in acknowledging that it gives me zero pleasure to dismiss a late-career work from a beloved entertainment industry titan who has given us so much. James L. Brooks co-created epochal television with The Mary Tyler Moore Show, Taxi and The Simpsons; he wrote and directed movies that explored complicated relationships with infinite wit and heart, notably Terms of Endearment, As Good as It Gets and the truly wonderful Broadcast News; and he has lent his imprimatur as producer to a string of favorites, from Big and The War of the Roses through The Edge of Seventeen and Are You There God? It’s Me, Margaret.

That’s quite a legacy, and at 85, Brooks deserves to look back with immense satisfaction on six decades of enduring work. In the interest of keeping that legacy untarnished, it’s to be hoped that the unfunny, painfully charm-deficient Ella McCay will be forgotten as swiftly as the writer-director’s last feature, the misbegotten 2010 Reese Witherspoon rom-com How Do You Know.

Emma Mackey stars as the title character, a law school grad who’s 34 and working at the State House in a small city (unnamed, but filmed in Providence, Rhode Island), when the story starts in 2008, in the middle of the recession. “A better time when we all still liked each other,” says Ella’s longtime assistant Estelle (Julie Kavner), who serves as narrator. A lot of people might not remember the years of the George W. Bush presidency so fondly — unless we’re talking comparatively — but it’s an early indicator of the rose-tinted gloss Brooks puts on even the most challenging situations.

Press materials state that Ella McCay was made as a tribute to 1950s screwball comedies, “punctuated by moments of drama in pursuit of truth telling.” Sure, Jan. When the results are this feeble, it’s probably best to keep quiet about auteurist intent. The movie is antiquated sitcom, very much in an ‘80s vein, its veneer of schmaltz garnished with a tinkling score by Hans Zimmer that should come with a sugar-content warning.

The idiosyncratic characters that feel so unmistakably real in Brooks’ best work, right down to their quirkiest eccentricities, are pretty much nowhere to be found in this script. Nor do the relationships make much sense with such a mismatched ensemble.

The story skips over Ella’s rise from political wonk to lieutenant governor in the office of Albert Brooks’ avuncular Governor Bill. We also don’t get a lot of detail on what prompted Ella to marry high-school sweetheart Ryan (Jack Lowden) when it’s tough to imagine him ever having been anything but a selfish douche. A single encounter with his pushy mother (Becky Ann Baker) should have been enough of a red flag. That one colossal misjudgment undermines our belief in Ella’s principled intelligence.

The writer-director is primarily concerned with tracing the traumatic experiences that have made her both vulnerable and guarded. The first occurs at 16, when she refuses to overlook the transgressions of her father Eddie (Woody Harrelson), who is forced to leave a senior hospital administration job after three women staffers come forward with sexual misconduct allegations.

Ella’s mother Claire (Rebecca Hall) still loves her philandering husband and is more inclined to forgive him. When she follows him to California for a fresh start, she encourages Ella to stay on with her stalwart Aunt Helen (Jamie Lee Curtis), at least until she finishes high school and goes off to college. The second major trauma is Claire’s death from cancer a year later, which at least gives Hall a dignified quick exit.

When Governor Bill is offered a cabinet post in D.C., he appoints Ella as interim governor. She hopes to use that position to further some kind of “Moms’ Bill,” providing early-childhood aid, and move local politics away from the donor-soliciting phone banks and out into the communities to do some real governing. That’s because Ella is caring and good, though it’s hard to recall a flimsier depiction of political idealism.

The career elevation comes at an awkward time, just as Eddie returns to town after 13 years’ absence, ordered by his unseen new love to put things right with his kids before they take their relationship to the next level. That means overcoming Ella’s hostility and bridging the divide with her uncommunicative kid brother Casey (Spike Fearn), an MIT graduate who has become an agoraphobic shut-in since his breakup with beloved girlfriend Susan (Ayo Edebiri).

The bigger hurdle comes when Ella’s indiscretions with Ryan in a government building come to light. Disgruntled with his role as First Husband and its limited perks, Ryan makes matters worse, rather than supporting her.

Salt-of-the-earth Aunt Helen — who runs a diner, just to make her even folksier — makes it her business to intervene in both the family frictions and political strife. But as irritating as Curtis’ feisty shtick gets, it’s nothing compared to Harrelson playing the twinkly-eyed and not exactly penitent rascal.

Kumail Nanjiani and Joey Brooks labor to milk the mildest of laughs from their material as the state troopers on Ella’s security detail; Lowden does what’s required of him in a thankless role; and Fearn earns some sympathy as the sibling most damaged by their father’s lousy parenting skills — though that doesn’t give his rapprochement scene with Susan any extra credibility. Even with an actor as warm and grounded as Edebiri, the relationship feels bogus. (With Opus, After the Hunt and Ella McCay back to back this year, the gifted Edebiri should be especially grateful for The Bear.)

Anyone nostalgic for the director’s more memorable work might get a kick out of seeing him reunite with past collaborators Kavner and Albert Brooks. But almost everyone here is trying way too hard, with the exception of Mackey, who’s appealing and natural even when stuck in a phony world full of phony characters.

In one of the screenplay’s leaden observations that pass for human insight, Casey whines, “Maybe we’re all just hamsters on the same wheel, beginning to wonder if the kid who bought us has lost interest.” With its corny catharses and thudding metaphors (Aunt Helen’s diner is on Hope St.), Ella McCay might make you want to jump off that wheel, especially as it edges close to the two-hour mark.