Rock Enroll - S5-E13
Visible crew/equipment: Towards the end of the show when they bring the cake out for Steve a crewmember walks past on the right of the screen.
Rock Enroll - S5-E13
Visible crew/equipment: When they are singing happy birthday to Steve near the end of the episode, a crew member can be spotted in the top right corner walking past an open door. (00:20:55)
It Didn't Happen One Night - S5-E2
Other mistake: When the folding bed contracts after Laura turns the lights off, it's very obvious the two legs sticking out from the bed are fake or that of a mannequin.
Answer: It is said that as Steve Urkel became a more popular character on the show, Judy became less important to the storylines, plus either her or her parents were demanding more money, causing her to be removed from the show entirely.