Deleted icons reappear on dock after reboot Well, I've been having some issues lately. While trying to get the USB WiFi antenna working again on my wireless bridge I found the adapter's light wasn't activating, so I tried plugging it into my iMac to troubleshoot. The computer didn't acknowledge the antenna when I plugged it in. Assuming it needed a driver, I rooted around and found a 10.7 driver pkg on the adapter's driver disc.

I proceeded to install said driver, and reboot. On reboot the device was still not recognized, but now the dock's icon set had changed. My dock usually contains Finder (Obviously), Firefox, Terminal, Settings, and Mission Control. However, now Maps, iBooks, Siri, and Photos were also on the dock, dispersed randomly throughout my other icons. On top of this both my docked app's custom icon and one of my docked folder's custom icons were reset (the icons were replaced by question marks, but the apps would still launch).

I've managed to fix the disappearing folder icon, however my app's custom icon is still missing on every boot, no matter how many times I fix it, and Maps, iBooks, Siri, and Photos still reappear in my dock in the same spots every time I turn on the machine. This was at first a minor inconvenience, but it has since become a major annoyance that causes me to hesitate to reboot or switch over to Windows at all, knowing I'll have to reconfigure the dock each time.

I've tried to delete ~/Library/Preferences/com.apple.dock.plist and ~/Library/Preferences/com.apple.dock.db, but unsurprisingly with no luck. This is a very oddly specific problem and I'm struggling to think of any explanation as to why this is happening or why a WiFi driver install package would even be able to cause this problem.

System in question is iMac 14,2 macOS Sierra 10.12.6. Any help is appreciated, thanks in advance. (BTW, I have since scrapped my old antenna and uninstalled the driver in favour of simply buying a better one, so it was definitely caused by something the driver installer did rather than a file it installed.
Maybe try both resetting and restarting the Dock. 

(I know you've already reset it, but I'll provide full steps below for the benefit of others):


Go to Finder
Press and hold the option key down
Now go to the Go menu
Select the Library option to open the User's Library folder. You can let go of the option key now.
Go to the Preferences folder (i.e. within the Library folder)
Find and move the com.apple.dock.plist file to the Trash
Now open Terminal (usually located in Applications > Utilities)
Enter this command killall -KILL Dock
Press enter
Re-add any non-default icons (i.e. apps) that you've added to the Dock, and remove any you don't want.