Hey there, jbstewart.
I see that the mouse cursor keeps leaving the window of the application you're trying to use. I'm happy to help.
How to turn on or turn off your Mac -- Restart your iMac then test the issue.
Use safe mode to isolate issues with your Mac -- Test how it responds in safe mode. If there are no issues, reboot normally and test again in your own user account. Remember this when booting in safe mode: Limited graphics performance in OS X recovery or safe mode
How to test an issue in another user account on your Mac -- If the issue is also happening in safe mode, use this article to test another user account. This will demonstrate if the issue is isolated to your account, or if it's system wide.
If another user account is already set up on your Mac, you can simply log out of your account (Apple menu > Log Out) and log in with the other account. But the best way to test is with a newly created account:
Let me know how that goes.