I’m not sure if it’s relevant but I have had slightly strange installations of Sketchup but since I’m new it may be a user error.
For example. I have Sketchup 2015 pro installed on my laptop and installed on my desktop. And I noticed that for a long while that on my laptop copy of Sketchup, when I picked the circle tool, I could not immediately begin typing the number of segments. It would not change anything in the indicator window until I started drawing a circle. But I’m not 100% certain that it was because of the copy or installation of Sketchup so take it for what its worth.