Using OS X 10.12.1 sidebar in finder is missing. Preferences are correct. I have edited preferences and relaunched finder and deleted com.apple.finder.plist and shutdown Mac neither method worked.
iMac, Mac OS X (10.7.3)
Finder/View/Show Sidebar.
I found an answer. You must delete com.apple.finder.plist and com.apple.sidebarlists.plist at the same time and reboot.
It could be a corrupt plist try deleting the com.apple.sidebarlists.plist
From Finder>Go>Do to Folder copy and Paste:
~/Library/Preferences/com.apple.sidebarlists.plist
Relaunch Finder >Force Quit>Finder>Relaunch
OSX 10.12.1 finder sidebar missing
