Revealing mistake: After Kenan gets his head stuck in the bars it becomes obvious on multiple occasions while Kenan is moving around that the "bar" on his right is fairly flexible, presumably made out of rubber for the benefit of the actor.
Kenan & Kel (1996)
1 mistake in Fenced In
Starring: Kenan Thompson, Ken Foree, Dan Frischman, Kel Mitchell, Teal Marchande, Vanessa Baden
Kel Kimble: Aw, here it goes.
Two Heads Are Better Than None - S4-E14
Question: Who screams the second time when Kenan tries to question Kel about the first scream?
Answer: Kel.