Mace's right arm is swallowed by the tree creature, but in the next scene, his left hand is shown with the injury.
Towards the end of the movie, Mace throws an ax into the back of Gorax's head, and it sticks inside. Then the next two shots showing that part of the Gorax's head shows no ax sticking out of the Gorax's head.
When Cindel is telling Wicket about the crash of her spaceship, the ferret they are playing with disappears and reappears between shots.
At the beginning when we first see Wicket, his mother has a baby Ewok held in her left arm with nothing wrapped around it. In the next shot, she has the baby in her right arm, wrapped in a leather blanket.
When Cindel is sick and coughing, a flower that Wicket gives her can be seen at her side before she has received it from him.
Mace's reflection is still visible on the pond after he magically disappears.
The spider that attacks the Ewok on the web bridge has visible strings.
When the mother and father are looking for their children in the movie, you can see cords hanging from their wrists.
The size of the Gorax in relation to the other characters varies wildly throughout the film. In some shots, it appears to only be about 10 feet tall, while in others, it's closer to 20 or 30.
The rope attached to the flyer that the father uses to find his two sons in the beginning switches from left to right.
Mace's effort to rescue his parents from the cage are pointless since the gaps are already big enough for them to fit through and the rope is in the cage to begin with.