Com.apple.finder.plist is missing and isn't being made automatically
The finder.plist isn't in /Library, it's in
~/Library/Preferences/com.apple.finder.plist
That would be why you couldn't find it.

Quick way to get there…
From Finder
 Cmd ⌘   N  for New Window
 Cmd ⌘   Shift ⇧   G  for Go To…
Copy/paste ~/Library/Preferences/com.apple.finder.plist including the tilde ~
Hit  Enter ⌅  

I'd also consider clearing the Saved Sate at
~/Library/Saved Application State/com.apple.finder.savedState
It's safe to delete the entire folder contents - data, window etc.