Try to Study! Pokémon Trainer's School! - S6-E15
Continuity mistake: When Max asks the headmaster if they, Ash, May, and Brock could go to Roxanne's class, the bottom of Brock's jacket changes from orange to brown. Also, Max goes from not being in front of Brock to being in front of him. (00:04:45)
On a Wingull and a Prayer - S6-E18
Other mistake: When Crawdaunt first appears, the bottom of its claws are mistakenly coloured red instead of cream. (00:09:25)
There's No Place Like Hoenn - S6-E3
Continuity mistake: When May looks at her bicycle when it is charred in her flashback, the emblem on her hat to the right of the knot on her bandanna is red with a white lining, but in the next shot, that part is white with a red lining. (00:06:41)
Continuity mistake: When Ash asks if Pikachu is ready for his challenge at the Dewford Gym, a poster behind a plant and a light go from being absent to being present. Also, the plant changes designs between shots. (00:00:03)
Continuity mistake: When Max says, "That's so cool, Ash," Ash's left index finger goes from not being completely covered by his badge case to being completely covered by it. (00:00:03)
All Things Bright and Beautifly! - S6-E13
Continuity mistake: When Venomoth is first eating, it is not on Chaz's right elbow joint, but in the next scene, it is. (00:04:53)
Continuity mistake: When Ash says, "Uh-oh," Pikachu's pose changes between shots. (00:00:45)
Revealing mistake: When Ash says, "Seems almost magical," the end of Pikachu's tail is missing. (00:03:59)
Revealing mistake: When first revealing a Lotad, the Lotad appears from nowhere. (00:02:10)