Perhaps, the problem is now narrow enough to identify the culprit. Now if Trimble wants to fix this problem, all they have to do is examine the OpenGL interface in the built sheets for Sketchup 20, pay particular attention to Windows global parameter settings (highly impacted by Windows updates), look at all the differences between the two OpenGL built (yes, I am aware that these are two different OpenGL versions). This narrows the issue to just the OpenGL interface. Now, if you go into the Preference panel on the Sketchup 2015 and disable the OpenGL hardware accelerator, then Sketchup selection will work albeit at the much degraded performance since the CPU is now doing all the work. Earlier versions of Sketchup can sidestep the Windows deficiencies). same computer set-up with same Windows updates and same graphics driver), why does one version works and the other won't? (For those who believe that this problem is not under Trimble control, I hope this experiment will settle it. Sketchup 2014 will work and Sketchup 2015 won't. Create a simple drawing, a single line will do. If your computer is affected, down load a copy of Sketchup 20. All you have to do is perform this simple test. (1) Windows update & (2) Not having latest driver). However, I can debunk the blames on the two most popular causes (i.e. Yes, I do have the Intel Driver Update Utility (version 2.8.0.7). In my computer I do have the latest Intel driver for the HD4000. I have done a quick analysis (SecondLife) for the issue which I am repeating it here:

There is a discussion forum in Sketchup here: It would take along time for the Select function to response.

Starting with Trimble's Sketchup version 2015, the OpenGL Select function appears to be broken.

Sketchup 2015 running slow windows 10