The freeze occurs on whenever attempting to change the icon image for a folder, shortcut, etc. using the context menu, choose "Properties", click on icon to choose a different icon.
The file selector window appears, but it becomes completely unresponsive.
The only way of killing the unresponsive window seems to run the following command from terminal:
killall nautilus && nautilus
After some google research the bug appears to have been solved in nautilus 3.22.
The link for the committed fix is