Several times over the past few months ive been frustrated with the new VFB and when it randomly stops accepting keyboard input. It doesnt let me type anything into any spinner. If i use the numpad it will randomly default to the 'arrow key' mode of the numpad even with numlock enabled. Numpad works fine in other applications. Even the numeric input on the main keyboard wont work when this happens. The spinner can be dragged to change the value but cant be typed in. It seems to happen at random.
I encountered this error back in v2 too. It appears to happen mostly with large scenes both during IR and rendering.