Twelfth Night, Courtyard Theatre, Stratford-upon-Avon

The setting for Gregory Doran's new RSC Twelfth Night is Eastern Mediterranean, Regency-style – all hookahs, Persian rugs, whirling dances and bushy-bearded Greek Orthodox priests.

You half expect Lord Byron to swan on, like Terence Stamp in Teorema, and really throw the bisexual cat among the sitting ducks in this version of Illyria. No such luck, alas. The production is fluent, forthright, and well-spoken, but it goes through the gender-bending motions without much in the way of illicit sexual electricity. It's decorative and decent enough and yet, where it counts most, rather dead.

The big draw is the supposedly piquant casting of TV's Victor Meldrew – Richard Wilson – as the Puritan steward, Malvolio. The (not un-commercial) thinking is that these figures are both grumpy killjoys and that sitcom's Mr Bellyache will put bums on seats. The trouble is that Malvolio is a great deal more than that, and that Wilson fails to find those vital extra attributes. You have to believe that the steward's repressive mentality and behaviour are a threat to society and the unlovely shape of things to come – and that, if you were to transfer him to Measure for Measure, he'd be sucking up to Angelo and jostling for obsequious position in the new, authoritarian regime. Malvolio has more in common with Angelo than with Victor Meldrew in terms of torrid imagination, too. You can say what you like about TV's poster boy for grouchiness, but you'd never feel inclined to call him a bit of a perv.

It's difficult to put this gallantly, but Wilson – who is also an excellent theatre director and latterly the maker of delightful television documentaries – is now more of an age where you play Firs, the elderly retainer in The Cherry Orchard. There's something oddly tame and audience-friendly about his Malvolio (from the outset), rather as if he was the human equivalent of one of those signs that declare "Danger: Guard Dog", in lieu of an actual canine. And the comedy sequences are very disappointing. The scene where he reads the forged letter is partly undermined by the large dreadful box-tree – a lumberingly jocose piece of scenery that wobbles and shakes with its cargo of eavesdroppers to the point where it upstages too much the epistle-perusing, gulled steward. The other reason it is not very funny is the interpretation of Malvolio's reaction here to the trumped-up news that Olivia (Alexandra Gilbreath) desires him. Wilson responds with goofy, denture-flashing wonder, whereas the deepest and funniest of exponents of the role show that the letter merely confirms the deluded, grandiose idea of himself that the steward has harboured all along.

A photograph of the actor is emblazoned on the posters and publicity for the production and Doran evidently sees the character as crucial thematically, too, because the final stage picture is of Miltos Yerolemou's chunky little woolly haired Feste and Malvolio glaring at each other alone. But when we look at this steward, whose final warning of revenge-to-come is shouted from offstage like a frantic afterthought rather than as a direct, fiery statement of intent, you don't think "poor old future", you think "sunset home".

I don't blame Wilson; it's Doran who has authorised this reading with him. And that's consonant with a production that throughout plays safe, full of unfunny farting jokes and never properly risky. For example, Richard McCabe's healthily dissolute Toby Belch at one point riles the steward by flicking whisky at him from his hip flask. The reference is evidently to holy water and ritual asperging. But here it just looks like yet another so-so sight gag. Even the concept of blasphemy seems alien to the world the production has created. It's super-competent, but this Twelfth Night feels like a GCSE lesson delivered by an over-matey teacher who is underestimating his pupils.

To 21 November (0844 800 1110)