If you were dreaming of people melting for reasons, it can mean they are disappearing because they are insincere, or no longer functioning. People who can’t come up to the mark (standard), can be seen as melting people in dreams.
In the past, some people believed in myths, folklore and non-logical realms. To see people melting into nothing was a type of magic, or sorcery. To dream of people melting could mean that a magic was directed at you. This type of dream is a warning that you are being targeted by someone in your work circle or social circle.