What happens with the level 1879?

Jeannette-7

Level 1879 has a bug. Ask to collect 3 yellow candies and you can not because the boosters become obstacles and not in yellow candies as required

StuckInATree

No at first it was thought to be a bug but it's deliberate, there's a way to make sure the mystery candies don't spawn into anything other than the yellow candy, it's just not very. https://care.king.com/en/candy-crush-saga/level-1879-glitch-or-deliberate