Batman VS Superman (2004)

Batman VS Superman is a DC Comics film that was scheduled to be released in 2003, to be based on Batman Beyond.

Plot
Lex Luthor manipulates a fight between Batman and Superman.

Why It Was Cancelled
The cancellation reasons are currently unknown. but it was likely because the crew was thinking that the film was much much worst

Result
In 2016, Warner Brothers released Batman vs. Superman to the big screen and got mostly mixed to negative reviews from critics and audiences.