Although there were early signs that ambitious plans for a Transformers cinematic universe were in trouble, following the disappointing reception for The Last Knight, the most damning evidence yet is the omission of the seventh film in the blockbuster franchise from the Hasbro-Paramount movie slate.

Originally announced for release in 2019, the untitled seventh Transformers film was set to follow the spinoff Transformers: Bumblebee (initially referred to as Transformers 6), which opens Dec. 21. However, Hasbro's new promo image for its upcoming film schedule shows no releases in 2019, and no Transformers movies at all through 2021.

RELATED: The End of the Cinematic Universe Began in 2017

According to fan site TFW2005, the toymaker said at its annual Toy Fair 2018 Hasbro Investor Preview that the live-action franchise will be rebooted following Bumblebee.

A promo image for the Hasbro-Paramount slate still includes the previously announced release dates in 2020 and 2021 for the "Hasbro Universe" films G.I. Joe, Micronauts, Dungeons & Dragons and an untitled "event."

The Last Knight, Michael Bay's fifth and final Transformers film as director, had been characterized as both "a final chapter and a new beginning" that would lay the foundation for a growing cinematic universe that, in addition to sequels and a spinoff, was believed to include an Autobots vs. Decepticons origin movie. Just last year, Bay teased that there were already 14 stories in development, the fruits of a Transformers writers room. The group's head, Oscar winner Akiva Goldsman, revealed in August that he's no longer involved with the franchise.

RELATED: Transformers: The Last Knight Leads 2018 Razzie Nominations

Although Transformers has never been loved by critics, The Last Knight rolled out in June as the worst-reviewed of the franchise’s five films; its $605 million global box office is also the lowest.

Directed by Travis Knight (Kubo and the Two Strings), Transformers: Bumblebee stars Hailee Steinfeld, John Cena, Jorge Lendeborg Jr., Rachel Crow and Pamela Adlon. The film opens Dec. 21.