There’s nothing necessarily wrong with the new stage version of the classic 1989 film “Dead Poets Society,” which is receiving its premiere Off-Broadway at Classic Stage Company and stars Jason Sudeikis as unorthodox poetry teacher John Keating (the role made famous by Robin Williams). It’s just completely unnecessary.

“Dead Poets Society” shows how Keating arrives at a teenage boys’ preparatory school in 1959 and encourages his clean-cut, dutiful students to be freethinkers, appreciate romantic poetry and just totally “seize the day.” Its central message that the humanities can enrich your life is always welcome to hear, especially at a time when anti-intellectualism seems to be winning the day.

The running time has been cut to about 90 minutes and some extraneous characters have been excised. As is always the case with a John Doyle (“The Color Purple”) production, it is visually spare. Instead of desks, the boys stand upon small stacks of books in order to give their climactic “Oh Captain! My Captain!“ salute to Mr. Keating.

But Tom Schulman’s script is essentially a rehash of his original screenplay, and the sentimental and solemn tone remains the same, which means that this stage adaptation brings almost nothing new to the underlying property.

Sudeikis has a chummy ease and subtle quirkiness as Keating, but he lacks the sadness and warmth that made Williams so unforgettable in the role. The young men (who sing in harmony and even hand out the programs) are all full of adolescent spirit, while David Garrison has a harsh edge as the upright schoolmaster.

It’s a decent enough production, but why should theatergoers pay big bucks to see a pale imitation when the original film can be viewed so easily? That being said, the limited run appears to be completely sold out.