There’s undeniable pleasure in sitting back and taking in the witty, overlapping banter, the chemistry and the “history” — pleasant and uncomfortable — that screen veterans Meg Ryan and David Duchovny serve up in “What Happens Later.”

But that’s basically the lone pleasure in this thin, cliched “old flames” relitigating their past in yet another snowbound airport rom-com.

Ryan, who directed and co-wrote this, revives a version of Classic Meg — Meg’s greatest hits — as a flaky but soulful “healer,” “cleanser” and “woo woo business” purveyor of “lightweight New Age b-s,” as her college years ex (Duchovny) puts it.

But he was once a “poet,” now an anxiety-riddled “businessman” with an acerbic take on the “personality” that drove him away from her. Like we can’t see holes in that theory.

Duchovny, with a few rom-coms and the quasi-romantic “X-Files” in his past, is well-cast as Ryan’s foil here, a guy who spies her first in this unnamed midwestern “regional airport” where a “thunder snow” “bomb cyclone” has trapped them both on their way to someplace else.

He avoids her on first sight, and when she spies him, she does the same.

But William “Bill” Davis and Wilhlmena “Willa” Davis do “meet cute,” and as the airport shuts down and their plight becomes obvious, they reconnect, reminisce, open old wounds and cling to old guilts, old hurts and old rationalizations over the course of an evening.

“What Happens Later” is practically a two-hander, a play set in a closing-then-closed airport with pretty much no other human interaction, just a PA system alerting our two players on the weather and directly speaking to each as they bitch about their missed flights plight.

They’re in their 50s — well, she “just pulled over at 49” — and have lived a lot of life in the decades since they were together in “Madison” (U-Wisconsin). He’s married with a kid, and “some things” going on with his marital status. She’s a 50something version of who she was way back when.

Willa’s flying cross-country with her “rain stick” to “cleanse” a peer/friend who just went through a breakup. From belief system to diet, from her once fashionable faux work boots and hippy farm dress to her unruly-as-ever-hair, she seems trapped as her 24 year-old self.

Bill has “anticipatory anxiety disorder” brought on by family, a job that has him traveling constantly, well into his ’50s, with a “bro” half his age as his touchy-feely boss.

Their history includes feelings, and burnished memories.

“My mom always said ‘That Bill Davis is a good guy.'”

“I always liked your mom.”

“Somebody had to.”

She claims to “remember everything.” He has bits of blunt criticism that he uses to explain their splitting up…to himself, anyway. But of course, it’s more complicated than that.

The trouble here is that it’s not more novel than that. The complications are predictable, and the narrative steps up to the plate with characters who are trapped in the past and fenced in as “types.”

The “cute” touches — that airport PA, business with phones and running away from each other (IN the airport) — aren’t that cute.

Ryan still has exquisite timing and has come out the other side of her botox/possible surgery years looking like the AARP-age pixie we always expected her to be. And Duchovny’s lost little off his faceball, but maintains the conflicted charm he always got across.

There’s just not enough to this — sparks, heat, longing, regret or wit included.

Did I miss the explanation of how these two have the same last name having never married? Maybe that slipped by with a “how we met” story that doesn’t appear to be have been addressed either.

And it’s hard to take much heart out of the message here. It turns out that “What Happens Later” is we’re all stuck, each with our own version of our past, one that doesn’t allow us to learn much from it.

That won’t keep anybody warm at night.

Rating: R, (limited) drug use, profanity, sexual references

Cast: Meg Ryan and David Duchovny.

Credits: Directed by Meg Ryan, scripted by Steven Dietz, Kirk Lynn and Meg Ryan. A Bleecker St. release.

Running time: 1:43