Robin Hood: Prince of Thieves (1991)
Set in 1194, Robin Hood: Prince of Thieves follows nobleman crusader Robin of Locksley (Kevin Costner) as he breaks out of a Jerusalem prisoner with fellow prisoner Azeem (Morgan Freeman). In the film, Robin Hood receives a telescope as a gift from a friend—but the device wasn't invented until centuries later in the 1600s.
Pompeii (2014)
Emperor Nero echoed the sentiments of Edna Mode: no capes. In 2014's Pompeii, some generals can be seen sporting purple capes, but Nero was known for putting anyone who wore purple capes to death.