If you cannot see the Edit with VocALign command in Studio One Professional or Studio One Artist version 6, please open the Studio One Plug-In Manager (View >Plug-In Manager) and click the Remove Plug-In Settings button:
Click the Yes button in the next window to confirm:
And click the Yes button again in the next window, to restart Studio One: 
After restarting Studio One, you should find the Edit with VocAlign command in the Audio menu.