Recently I was helping a good friend of mine build a privacy fence in his backyard. Nothing too complicated: five posts, ten bags of concrete, one gate, treated lumber, and dog eared pence panels. Before we could begin though, we had to rip out the preexisting chain link fence. The demo went pretty smoothly, except for one small (so we thought) problem. The center chain link post (where the new gate was going to be) was embedded in a slab of concrete. Not a problem, I thought. Just use the Skilsaw with a diamond tip blade and cut a square into the concrete and pull the baby out.
Not so simple. The concrete slab was twice as deep as the saw blade would go. So next was the sledge hammer and chisel. After about an hour of blood, sweat, and tears, we managed to break through the entire slab, only to discover that the metal post had first been anchored with a separate concrete pour two feet deep.
Now at this point, two wise men - which apparently we are not - would have stopped trying to chisel away at the mangled mess of concrete with a circumference larger than the square hole on the surface. But not us. This had become personal.
"Never give up", we said. "Never surrender."
So we toiled on - for two more hours - chiseling away among a tirade of four letter profanities, only to eventual come to our senses. We were not going to win this battle, at least not in the way we were trying to do it.
Solution: We cut off the metal post, filled the hole with concrete, and secured a 4X4 anchor bracket. Problem solved. However, the problem could have been solved much sooner and simpler had we given up our futile attempt earlier. To never give up - never! under any circumstances - is just stupid. And this is true for all things, screenwriting included.
In the development and writing stages of your script, you will run into roadblocks - plot points, character arc, story situation, sequence structure, etc. - but if you force it, trying to smash that square peg in the round hole, your script will suffer. But you still must find a solution, and asking questions, using a story questionnaire and character questionnaire, is a great place to start.