It seems there are many tools, such as the knife tool, that cause the viewports to lock up when you are "in" the tool. By "lock up" I mean that while in the tool I cannot rotate, pan, or zoom the view. This would be super handy and seems like a no-brainer. Thanks for your help! -Ben
I figured out my problem. I am using a 3Dconnexion 3D mouse and it does not manipulate my view while a tool is active. The normal mouse/keyboard ways of rotating etc do still work as expected while a tool is active.