Nice try.  All my hidden icons were actually hidden before I installed tweaking.com registry back-up.  Then in Win10 tweaking.com, I do a registry backup and then I do in Win10, a registry restore with the so called hidden icons clustered around the little taskbar box that should hold them.  Then I restart Win 10 and do another tweaking.com registry restore.  Guess what - three of my five so called hidden icons are clustered around the little box on the taskbar.  This is the same as before I re-started Win 10 after doing the registry restore.  
   
So then because I do not like to backup anything in the entire Win 10 operating system while I am actually in Win 10 - I put the Win System Repair disk into my CD drive; got my BIOS (which of course is not a BIOS anymore) to boot from the CD drive; and finally was in the (what tweaking.com calls), the Windows Recovery Console.  Then I am in DOS, ie the 25 year old operating system that Microsoft stole from the genius that created DOS.  
  
So now using DOS commands, I restore the registry that I just back-up maybe 3 hours before.  So I take the recovery CD out of my CD player and re-boot Win 10.  Guess what - all the hidden icons should be hidden in that little box on the taskbar, are where they should be.  
   
I thank you for your concern, but I think tweaking.com should have a way to report obvious bugs.  The problem here is that every little stinking problem would be reported to tweaking.com.  I would have the administrator of this forum review on a daily basis and report anything that could be a programming bug to tweaking.com.
   
I just joined this forum a few days ago and think that is like the blind leading the blind.  (I am 70 years old and just love to use expressions that are 60 - 70 years old).  
   
I looked at another post on this forum from a user who had been using this web site for 2 years and had a problem that should actually work,  I think the whole problem is Win 10.  You know that we are just doing the Beta testing on Win 10.  For me I always do a complete backup of my C drive using Macrium Reflect before ever installing any new software.   
   
This is the second time I am trying to do  backup-restore of the registry.  So I have tried 3.5.2 & 3.5.3.  Maybe when the next revision comes out, tweaking.com will get its act together.  So don't stay up late at night trying to resolve my problem.  I will continue to monitor this post to see if I have overlooked some item, but I doubt it.  
    
Thanks for your concern.