It’s possible to write yourself into a corner with a plot that doesn’t work. Save a backup copy. Then start deleting your most recent paragraphs, scenes, or chapters, working back to the last place you remember being satisfied. Start again from there.
This tip is from 19 Tricks to Shatter Writer’s Block. If you missed any of the previous tips, you can find them all in the Hack Your Noodle section of Read Write Repeat.