The Flash

For a number of years, a film based on the DC character The Flash had been in development since the 1980s. David S. Goyer even planned on making the film after Batman Begins.

Plot
The plot is currently unknown.

Why It Was Cancelled

 * 1) The reason for cancellation was due to creative differences.
 * 2) Another contributing factor to the cancellation was the Writers Guild strike of 2007 to 2008.
 * 3) Shawn Levy went on to direct Night at the Museum: Battle of the Smithsonian.

Result

 * The film was permanently cancelled.
 * A new film starring Ezra Miller and Michael Keaton, returning as his portrayal of Batman from Tim Burton’s 1989 film and Batman Returns will release on November 4, 2022