Lindsay Lohan’s not exactly an old pro at rom-coms. But as she’s a producer on her new film, one would have hoped she’d do the homework that would tell her how they function, what pay-offs they need to deliver and how important chemistry is.

Setting can be a plus, supporting players should be amusing and colorful. And the leads absolutely positively have to “click.” Take care of those concerns, and parking the redhead into a romantic comedy set in Ireland should have been a slam dunk.

It’s not. That’s not really on her, but as she took that producing credit and deepens her connection to Netflix, it might have been nice if she’d insisted on someone with more than mawkish Hallmarkish “Christmas” romances on her resume as director, and pushed for a rewrite that spiced up the sparks between her and co-star Ed Speleers.

Because, saints preserve us, one and all wasted a good trip to Ireland with “Irish Wish.”

The last half of the third act has the right energy, if not the jokes and romantic whimsy that the entire movie cries out for. It’s just not funny enough, not romantic enough and not Irish enough to come off.

Lohan plays Maddie, a New York book editor who swoons over Paul (Alexander Vlahos), an Irish author who became a star thanks to her endless rewrites. She thinks he’s going to propose, the silly thing. Her mother (Jane Seymour) knows this, but not Maddie’s friends, who meet her for the most glamorous book-reading/signing ever.

That’s where bestie Emma (Elizabeth Tan) makes eyes at the author and next thing we and Maddie know, she’s boarding a plane for Knock Airport in the west of the Olde Country for Paul and Emma’s big fat Irish wedding.

Sure, Maddie met a rude local (Speleers of “Downton Abbey”) at the luggage carousel. But that “meet cute” with a photographer isn’t spirited or amusing and holds little romantic promise.

If only she could make a wish by an enchanted lake in Old Eire, sitting herself on the stone wishing chair and praying to Saint Brigid (Dawn Bradfield) to make her Paul’s bride to be.

And so it shall be. She wakes up with a fellow she’s pined for, scrambling to ensure the wedding his stage-directing mother (Jacinta Mulcahy) always dreamed of, and noticing that there’s still “something” between Paul and Emma, and that there might be “something” in this nature photographer James (Speleers) that she’s drawn to.

Lohan’s third act cameo in the musical movie revival of her earlier triumph “Mean Girls” was the most charming thing in that sometimes grating and oversexed “remake. If we can root for Robert Downey Jr., who put himself through some things, we can surely still pull for Lindsay.

But as much as we root for Maddie here, it’s hard to see her engagingly paired-up with any of her co-stars. Lohan’s still a likable presence. But Speleers’ James lacks the roguish edge of say, a Matthew Goode in the middling-but-still-better-than-this “Leap Day” Irish rom-com of some years back.

This “Irish Wish” sits uneasily in the gap between “competent” and “moderately inspired.” The hints of local color — a twinkly priest (Aidan Jordan), a generic barman (Tim Landers), a few lovely settings, including The Cliffs of Moher — just aren’t enough to deliver the charm the picture sorely lacks.

Rating: TV-G

Cast: Lindsay Lohan, Ed Speleers, Alexander Vlahos, Elizabeth Tan,
Dawn Bradfield and Jane Seymour.

Credits: Directed by Janeen Damian, scripted by
Kirsten Hansen. A Netflix release.

Running time: 1:33