Finder Preferences locked
Mac OS 10.12.2 (latest): Since updating I cannot change any of the Finder Preferences. If I click on any change, as soon as I release the mouse, the change is abandoned and the selections revert to the default. Also, I cannot change any of the Finder view options. Instinctively this seems to me to be a problem with PERMISSIONS somewhere in the Finder setup. But... OSX Disk Utility no longer offers Permissions Repair.
Any pointers how I can unlock my Finder?