HBO lost $30 million on a canceled Game of Thrones prequel, but the series had an unavoidable issue from the start. Game of Thrones' final season didn't go as planned for HBO, with story issues and production problems overshadowing Westeros' much-hyped battle with the undead White Walkers. Fans and critics complained about everything from the episodes being too dark to modern water bottles appearing in the background of scenes. The show's final episodes received so much fan backlash that they even inspired a viral petition to redo season 8, and the negativity found its way into the cast's WhatsApp group chat.

HBO has several Game of Thrones spinoffs and prequel shows in the works, including the upcoming House of the Dragon. The series, which takes place around 200 years before Game of Thrones, tells the bloody history of House Targaryen. The first trailer for the series introduced several key players fans should know. For instance, Paddy Considine's King Viserys Targaryen, Emma D’Arcy's Princess Rhaenyra Targaryen, and Olivia Cooke's Alicent Hightower were all featured. However, Matt Smith's Daemon Targaryen steals the show in the teaser, hinting in narration that he may make a play for power in Westeros.

Related: Game Of Thrones’ Final Season Failure Is A Good Sign For The Books

HBO's canceled Game of Thrones prequel cost the network millions, but it always had a looming problem. The series, which author George R.R. Martin had a hand in, was set to take place thousands of years before the events of Game of Thrones, recounting the origins of the White Walkers and the legendary history of Westeros. The show also had star power, with Naomi Watts hired to front the series. But, unfortunately, season 8 soured fans on a White Walker origin story, so an entire series on the creatures didn't make people particularly excited.

Split image of a white walker, a wight, and the Night King from Game of Thrones

Game of Thrones season 8 tanked HBO's prequel before it even began. Ahead of season 8, HBO endlessly promoted an impending battle with the White Walkers in its marketing and trailers, hinting that the conflict would take center stage in the final season. Then, in one stab of Arya Stark's (Maisie Williams) dagger, the Night King (Vladimír Furdík) was dead, and the White Walker threat was over. HBO's choice to breeze by the White Walkers irked fans since the show had teased the battle for years. However, the move also proved that the White Walkers' motivations and true intentions didn't matter. Arya didn't just kill the White Walkers with her dagger. She killed any reason for the Game of Thrones prequel.

HBO knew just any prequel wouldn't work following Game of Thrones' criticism. Ahead of season 8, it appeared Game of Thrones could do no wrong in the network's eyes, but the final season gave a harsh reality check. And in James Andrew Miller's new book, Tinderbox: HBO's Ruthless Pursuit of New Frontiers, former WarnerMedia chairman Bob Greenblatt said he saw a cut of the prequel and didn't think it delivered on the promise of the original series. So it's clear the canceled Game of Thrones prequel had structure issues regardless of its story, but its premise had it doomed from the start.

More: One House Of The Dragon Change Hints Why Game Of Thrones Failed