The Smurfs 3

Note: Please do not add that "The Sony Hack was going on" as a reason here, because this was before the Hack occurred.

The Smurfs 3 is a proposed third installment in the CGI/live-action Smurfs franchise. The announcement was made about two weeks after The Smurfs 2 was released in theaters. It was originally set for a release in 2015, but was cancelled.

Plot
The film was possibly going to have the Smurfs be in a different time period.

Why It Was Cancelled

 * 1) Sony wanted to make an animated Smurfs film.
 * 2) Jonathan Winters, the voice actor of Papa Smurf died of natural causes on April 11, 2013 before the film was made and Anton Yelchin, who voiced Clumsy Smurf died from blunt traumatic asphyxia after a freak car accident between June 18 and 19 of 2016.

Results

 * The Smurfs 3 was permanently cancelled and the live-action/animated Smurfs films became a duology.
 * The Smurfs series was rebooted in 2017 with a fully CGI animated film titled Smurfs: The Lost Village.

Trivia

 * It was going to be about time travelling back to possibly 1878.