The writing was on the wall when Fox’s live production of “Rent” opened with a hefty asterisk: This musical event, despite every effort otherwise, was “previously recorded.”

As the cast explained after the first commercial break, the actor in the lead role of Roger (Brennin Hunt) broke his foot during dress rehearsal the night before, and when everyone realized the extent of the injury, a call was made. Instead of performing live as planned, Fox decided to mostly just air the footage they’d already taped, with the exception of a hastily re-choreographed final act that could include Hunt, plaster cast and all.

The situation was, to say the least, not ideal. But the decision to air what was supposed to be a run-through made an undeniable difference in a production full of distractions.

Many actors were noticeably (and understandably!) saving their voices and energy for the real thing they believed was yet to come. The first half especially felt more listless than “Rent,” a musical that lives and dies by enthusiasm and adrenaline, ever should be. Notes that should have soared petered out, waiting to truly wow the next time the curtain was raised. Alex Rudzinski, who recently directed the hell out of “Jesus Christ Superstar” live for NBC, defaulted to so many swooping cameras that Jason Sherwood’s impressive production design kept getting lost in translation. The sound mix only rarely figured out how to balance the band with the vocals, let alone the screaming crowd surrounding them all.

When it finally went live, the difference — both with the Fox cast and the original Broadway cast that joined to sing the moving curtain call performance of “Seasons of Love” — was palpable, and all the more frustrating for it. In fact, some audience members at tonight’s show tweeted videos of the cast performing live around Hunt, belting from a wheelchair — and even those had more vibrant energy than the pre-taped version millions were watching instead.

It’s of course unfortunate and unfair when a performer can’t perform for reasons outside their control, but that there was seemingly no contingency plan at all is also unfortunate and unfair for both the production as a whole and the performers who didn’t realize that their first run was going to be their last. By all rights, this should act as a cautionary tale for future live musicals that would have otherwise gone forward without securing understudies. Yes, all of the recent live musicals have emphasized the star power of their cast, and “Rent” did the same when it assembled names like Vanessa Hudgens, Tinashe, and “Jesus Christ Superstar” standout Brandon Victor Dixon. Letting someone go the day of the production was probably not an option Fox wanted to exercise. But having formidable understudies who can step in and deliver when a star can’t has always been a cornerstone of musical theater. It should be no different for the televised versions for situations exactly like this.

Outside the dress rehearsal disaster, one of the weirder side effects of “Rent” airing on Fox is that “Rent” could never be itself on Fox. Jonathan Larson’s musical became a sensation when it premiered in 1996 because it used traditional operatic and musical structures to portray poor New Yorkers — many of whom are queer people of color — struggling through the AIDS crisis. It’s explicit about sex and drugs and the intimate lives of LGBTQ people, and defiantly so.

Fox’s “Rent” did what it could to preserve the original spirit by keeping as many of the original lyrics as possible, but there were, as was maybe inevitable, some confusing tradeoffs. (No “dildo” in “La Vie Boheme, but “faggots, lezzies, dykes” made the cut? Oh, to be a fly on the wall in these lyrics negotiations…) They even managed to pull off “Contact,” a slinky interlude slash interpretative dance break that goes from sexy to tragic within minutes. Confusing lyrics tweaks and all, in truth, it’s pretty incredible that “Rent” aired in primetime on a broadcast network at all, especially with all its queer characters largely intact — and openly making out, besides.

In that respect, it’s no surprise at all that most of the best moments of Fox’s “Rent” — and the show in general — squarely belong to its queer characters. Kiersey Clemons brings a welcome grounded energy to the role of Joanne, a pragmatic lesbian determined to slash through all the red tape she can find. Dixon’s performance as the earnest Collins — especially opposite a game but outmatched Valentina as his partner, Angel — is a forceful reminder of just how talented he is. (His gorgeous reprise of “I’ll Cover You” left his castmates in tears, even in dress rehearsal.) And no one seemed to have told Hudgens that the Saturday performance was a dress rehearsal, because her vulpine Maureen, a flirtatious performance artist with charisma to burn, storms the stage with so much urgent fire that you can practically feel the heat emanating from the screen.

Even with these highlights, though, too many factors made Fox’s “Rent” too scattered to ever truly land like it could have, which is a shame. It had a game cast, production value to spare, and a powerful message of queer community that could have made a true statement, if only it knew how to focus on what matters.

Cast: Kiersey Clemons, Brandon Victor Dixon, Jordan Fisher, Vanessa Hudgens, Brennin Hunt, Mario, Keala Settle, Tinashe.

Crew: Executive producers: Marc Platt, Adam Siegel, Julie Larson, Allan Larson and Revolution Studios’ Vince Totino, Scott Hemming and Marla Levine .