Watch that none of you err. (Matthew 24:4)The term that he uses for erring is πλανήσῃ. This verb is used in the Book of Enoch to describe the erring messengers. It is also the same root where the term planet comes from; a planet is a wandering star. The warning is against wandering away from what Jesus lays down.
In looking at the last days, it is not uncommon for individuals to wander off the right way, and Jesus does not want his disciples to stray from the path. Why they might wander is related in the next verse.