I am unable to add another W2

If this is a download version, you can shut down TurboTax or Force Quit if necessary, then reboot your MAC. Then go back to the program and select Add a W2.

If this is TurboTax online, close out of TurboTax, then please clear your cache and cookies.  Log back in and go back to the income and wages, then select add a W2 again. 

Thanks Vanessa. I discovered that when the page repopulated it did so off screen. I simply had to scroll up on the blank page to see the new content at the top.