Continuity mistake: In the introduction, when TJ pulls the ball off Gus, Gus is covered in gum. When they are walking into the school, the gum has disappeared.
Continuity mistake: Carter and Cadet Haley enter the Stargate and we see them through the "puddle." When they come out on The Other Side, their positions are reversed.
Clash of the Megazords - S1-E29
Other mistake: When TJ goes to get the Phantom Ranger's ruby, he is standing on top of the battery pack on the Turbo Megazord. There are no other places for him to stand. After he destroys and knocks off the battery pack, in the next shot he is still standing in the same place, but there is nothing for him to stand on.
Super Nova - S1-E2
Revealing mistake: When Stan, Xev and Kai are walking to the Memory Chamber, they seem to walk out of a two dimensional line at the lower left into the scene. The set and green screen weren't quite synched.
Continuity mistake: The fish that Harley uses to protect herself from the Joker changes shape and size every shot.
Continuity mistake: When King mentions the two brothers' "destiny", his big feline is at Young Diabolik's side, facing King and the others. Aerial shot, and the panther is at King's side facing Diabolik. (00:05:00)