Simple Removal of Stuck Sink Stopper

try turning the top of stopper with fingers. They are generally " locked in with a twist" and can be unlocked the same way. good luck!

We just experienced the problem describe in this question. A dinner guest pushed the strainer stopper past the Blanco flange over the disposer and the stopper could not be removed by pulling straight up. The Blanco flange is difficult to remove so we knew that removing the flange would be a last ditch effort. I tried using several tools trying to deform the stopper enough to lift past the lower part of the flange but without success. While I was on the internet looking for a solution, my wife found the obvious answer. She pushed the stopper down into the disposer, rotated it 90 degrees. She then aligned the edges of the stopper with two of the small indents in the lower part of the flange. The stopper was then pulled up past the flange where only two points on the circumference of the stopper contacted the flange.
Kudos to her for this simple solution.

If it's not visible from above then you must remove the trap j-bend. Go under the sink and put a big bowl or tray under the trap because when you remove the j-bend water will come out. You'll need a 12" grooved pliers, like channel locks, to get the nuts off. There are two of them. If the trap is old brass or chrome you may end up cracking the j-bend. If it's white or black plastic you can probably remove the nuts by hand. Look in the j and pull out your stopper. If it's visible from above a long pair of needle nose pliers would work best to remove the stopper.

probably hair stuck in the drain. did you remove the stopper "pop up" if no hair or blockage there or in the trap, then its further down, you will need a small snake. 1/4 inch cable works well in bath and kitchen drains.
you can purchase one at home depot.