What is your operating system?
Also see Adobe help file:
You need scroll bars to scroll the window vertically as well as horizontally.
I'm using Mac OS 10.9 -- Maverick
According to Apple website you need to do this:
You can activate this option in System Settings -> General -> and under “Show scroll bars” choose “Always”.
See this link:
I don't use Apple MACs so I can't help you further.
What happens if you click the green button?
Hello Barbara B.:
Almost nothing changes--just the slightest minimizing and maximizing of the screen.
thank you for the link and advice.
nothing has changed though