After updating, I can no longer Option-Click and drag to move the viewfinder.
What do you mean ‘move the viewfinder’.
When you first ran 2.78 did you use the option to copy your previous settings ?
Did you have ‘Lock Camera to View’ enabled in the properties bar but now have it disabled
I used to be able to freely move the angle that I’m looking at the scene from, in the 3D view, by holding Option and click-dragging with the mouse. Now when I do that, it doesn’t respond. Everything else seems to be working correctly, just not that one function. And Lock Camera to View doesn’t change anything, whether it’s on or off.
Where can I copy previous settings? I installed 2.78 on the same system and launched it, but I didn’t see any option like that.
Found it! I had “Emulate 3-button mouse” checked before, and it’s not checked now. Once I turned that on, the Alt+Mouse Drag worked again to change the viewpoint. Thanks!