OS X Yosemite brings a new host of features and functionality to OS X, and some problems as well. One of the more vexing issues that's popped up is a problem that causes the save screen to grow longer and longer until it scrolls right off the bottom of the screen.
Turns out it's a bug, and a pretty ugly one too — I have no idea why Apple thought it was acceptable to let Yosemite ship with this glaring mess-up. Over at his Six Colors blog, Jason Snell explains what's going on:
According to [Jon Gotow of St. Clair Software], what happened is that Apple changed the file dialogs so that the title bar is now considered to be part of the window—and changed the math everywhere except in save sheets.
The trick to fixing it involves popping open Terminal and copying and pasting a command to delete a preference. Follow the link below for details.
Source: Six Colors