There comes a point when every writer wonders why they've done all they can to make something work and it just won't.
You write a scene or chapter, you know it lacks something but you're not sure what. You show it to a few people, or post it for review on one of the many peer review sites available. You get some lukewarm responses, usually contradictory on the finer points, but agreeing that IT LACKS SOMETHING. One reviewer says the pace is too slow, another there is too much description, another the characters are one dimensional, another the situation is unconvincing.
After a lot of soul searching and gnashing of teeth you get to work slashing and burning your beautiful prose and rewrite. You post it again, and guess what. The reviewers, though contradictory on the finer points, agree IT LACKS SOMETHING.
So now you have a choice. You can continue this process until:
a. You get so sick of it you give up writing and become a Trappist.
b. You get so sick of it you become beligerent and eventually get thrown out of the group.
c. You go mad.
d. All of the above.
But don't despair. There is another option. Sometimes a scene/chapter will not work. There are many possible reasons for this; you might be approaching it from the wrong angle, you might be too close to the subject matter, your story may not be worth telling after all. Whatever the reason, you have the choice to just walk away. Stop flogging this dead horse and get on with something else. It's a very important lesson to learn, and you'll never make it as a writer without digesting the important fact that not all the outpourings from your pen are worth giving the time of day.