Can't change release year on unreleased film

The film 'Cousins' (https://www.imdb.com/title/tt3390014/), starring Jerry Stiller and Marvin Silbersher, has never been released. It has (2013) as it's release year next to the title which is, I think, the year it was filmed. Apparently the film was completed, according to Bruce Bertrand who did the cinematography (see https://www.linkedin.com/pulse/great-pleasure-jerry-bruce-bertrand) but besides a private screening which Stiller attended, the film has never been shown publically. Bertrand states the film was hard to market as it was improvisational and has no plot, which might have contributed to it's non-release more than 10 years later. I have no idea whether the movie will ever actually be released, but seeing as it has not been released as of yet I tried to change the year to (????) but got declined saying "The year in the new title must match the year in the old title." Can anyone help out?