Reset to Default Keyboard Commands

I somehow have created a situation where I can no longer mouse zoom in windowed or full screen mode. 

In windowed mode, I can pan around when holding the space bar, but the mouse zoom does not work. In full screen mode, I can neither pan nor zoom with the mouse when pressing the space bar.

However, if I​ go to mouse look mode, shift+O, then I have full pan function in windowed and full screen mode. I have Opus installed, but I have never deliberately setup any cameras or views with that utility.

Any ideas on how to get back to default function where I can press the space bar and pan/zoom in any window mode?

Thanks