Resize your monitor...on a Mac go to your monitor preferences.

I experienced the same problem.  

The only solution that worked for me was to move the window laterally to the right.  In doing so, the blue "accept" button could be seen in the sliver of screen to the right of the bottom icon row.  I could only see a small sliver of the button but it was enough to allow the mouse to select.  

Try, with TurboTax running, Top menu bar -> View -> Hide Tool bar, and then again uncheck "Show Toll Bar" at the top. They should both move the window up.

You can also use System preferences -> General -> Automatically Hide and Show top menu bar that will also move the windows up.

You can also use System Preference -> Dock and move the dock to the left or right side of the screen which will provide additional room at the bottom.

Some have said that clicking the "green dot" at top left of the window expands the entire window to fill the screen and the box is accessible.