I'm currently using Windows 10 Pro. I've noticed that at seemingly random times that I will lose icons in my system tray area. Whenever this happens I immediately right click the tray, bring up the settings, and click on "Select Which Icons Appear on the Taskbar" under "Notification Area". The programs I've lost from the System Tray are listed and are set as being on, but the icon next to them is blank. The unaffected programs that are still in the System Tray are also still set to being on and they have their icons where they should on the list. Switching the button next to the affected icons from On to Off and On again does not fix the issue. Only manually starting up each program again and restarting their system tray icon options fixes them. I've run Event Viewer after the most recent occurrence and it did not show anything odd having happened at the time. I'm attaching a screenshot. Two of the programs in question are NVIDIA Settings and PowerChute System Tray Power Icon (my surge protector program). Hopefully someone knows what causes this to happen. It's never a set time of day when this happens. Seems to be completely random and it doesn't happen everyday either.