Revealing mistake: At the beginning of the episode, Dr Smith is painting a painting. The commander picks it up and questions it. Smith grabs it back and puts it back on the easel but puts it in a different direction but thinks nothing of it.
Lost in Space (1965)
1 mistake in The Challenge
Starring: Guy Williams, June Lockhart, Mark Goddard, Marta Kristen
Robot: My micromechanism thanks you, my computer tapes thank you, and I thank you.
The Great Vegetable Rebellion - S3-E23
Trivia: Due to their uncontrollable laughter during filming of the infamous "Vegetable Rebellion" episode, Guy Williams and June Lockhart were written out of the next two episodes.