I've tried re-starting, using a magic keyboard and the keyboard on my Mac Book Pro, I'm running macOS Sierra v 10.12.2 and also McAfee Livesafe. Didn't have any problems until today, and it's driving me crazy! It's not only shift-click to select multiple objects on the page, and I don't want to click and drag to select items. It's also option-click to clone and object, seems to show the double pointer for a second and disappears and doesn't work, also command-spacebar to zoom in and out doesn't work. Can anyone help with this please?