Dreaming of quicksand depends on how you want to take it. As per dream interpretation and meaning, it is a kind of warning and therefore you can use the dream to overcome future problems.
Dreaming of you in quicksand means your past activities will come to haunt you. All the bad things you have done in life will stand in queue and take revenge.
Dreaming of you simply seeing quicksand means you will get opportunity to correct your past mistakes and come out clean.
If you dream of other people trapped in quicksand means you will face accidents during journey. It also means you will face damage due to natural calamities.
Dreaming of family members or relatives or friends trapped in quicksand means you will soon hear a news about death.
Some people dream about quicksand after seeing movies, quick sand related news or incidents or quicksand documentary. Dreams after such incidents have no value. The dreams have to happen naturally without any influence of day time events.