When a hit television show gains popularity, movie producers, filmmakers, and studios are quick to capitalize on the sudden fame of its stars. But the results are not always good. Three years after “Friends” went off the air, the stars of NBC’s last mega-hit are still spinning their wheels in an effort to find success outside of their memorable characters.

These days, it’s the stars of NBC’s new hit, “The Office,” who are fast becoming acquainted with the pitfalls of feature film. First, Steve Carrell donned a white beard and a tunic for the dull and sanctimonious “Evan Almighty.” Now, a tortured John Krasinski finds himself lying in bed with Mandy Moore and Robin Williams for the humorless “License To Wed.” This tale of an overbearing priest and a confused young couple may not be in the same category as the Matt LeBlanc monkey-playing-baseball film, “Ed,” but it ranks close to David Schwimmer’s funeral non-comedy, “The Pallbearer.”

Director Ken Kwapi , who filmed the pilot of “The Office,” brought his star from the series. Mr. Krasinski here plays Ben, a groom partaking in a pre-marital counseling course with his fiancée Sadie (Mandy Moore) and must grapple with a terrifying priest named Father Frank (Robin Williams). Also appearing are Angela Kinsey and Brian Baumgartner, who make up two thirds of the inventive accounting department on “The Office” and wallow here as a jewelry clerk and a fellow groom, respectively, in Father Frank’s marital counseling course.

None of the film’s stars can overcome the film’s generic attempts at comedy. Although Mr. Williams brings his patented method of scenery chewing to distract from the lack of humor, nothing can mask the underwhelming script.

“License To Wed” is premised on the “hilarious” concept of a couple being made to consider why they are getting married before the wedding. But the montage of Ben and Sadie’s courtship slides by so quickly that the impetus for their impending nuptials seems based solely on mutual adorableness. They are predictably surprised when the priest expects them to engage in a premarital counseling course before they wed at his church.

It might have been amusing to see what strange habits the lovebirds reveal to each other in the process of Father Frank’s course, but “License To Wed” is more interested in plumbing the depths of Father Frank’s depravity as he tries to lead them toward marital bliss.

Father Frank seems like he would be more at home in a 1970s horror film than a modern romantic comedy. He spies on the couple, appears in random locations, and generally tries to ruin their lives. At all times he is accompanied by a diminutive sidekick (Josh Flitter) who must be present for comedic relief but seems more likely to go into headspins at a moment’s notice.

Despite the fact that most of the film takes place in and around a church, “License To Wed” fails to bring any religious lessons to the foreground. Ben and Sadie never profess to care about religion. Perhaps for fear of offense, it is never clear what church Father Frank represents. His marital lessons are resultantly more physical than spiritual. To test their sturdiness as a couple, Father Frank forces Ben and Sadie to fight, gives them ugly fake babies to carry around so they might learn about parenting, and puts them through an extreme course of driver’s education for couples.

As it all plays out, Ben and Sadie are worried to learn that they have large differences. For instance, boring Ben wants two children, while submissive Sadie wants four.

Trying to capitalize on Mr. Krasinski’s aptitude with uncomfortable silences on “The Office,” co-screenwriters Kim Barker and Tim Rasmussen have based the character of Ben on little more than confusion and exasperation. He is a whipping post for awkward moments, irritating and otherwise. Ms. Moore similarly wallows as Sadie. She is adorable as always, but fails once again to add anything appealing to a mediocre role. Together, the characters are too busy dealing with Father Frank’s attempts to disrupt them to develop much of a rapport.

The supporting characters exist solely to propel the action, and with the exception of a nuanced performance from the underrated Christine Taylor, they fail to distinguish themselves. Ms. Taylor plays Sadie’s depressive divorcée sister with a subtle wit, despite the randomness of her character. When Ms. Kinsey and Mr. Baumgartner arrive, there is hope that they will jumpstart the background, but there is nothing for them to work with.

At the completion of Father Frank’s course, the couple seems no different, save for a few battle wounds. At least the continued success of “The Office” ensures that the actors here will have ample opportunity to try again with film.

mkeane@nysun.com