I regularly work on a larger screen and last time I enlarged the height of the commit dialog for a better overview.
Problem:
Now when I reopen SourceTree to work on my laptop without external screen the bottom parts of the commit dialog is outside the screen. It is impossible to use them to commit my work. I see no way to scale the commit dialog back to a smaller format.
Solution:
Always check the height of the screen and make it impossible to open a dialog that is larger than the screen.