Macbook Pro TrackPad not clicking I'm using a macbook pro, now the TrackPad could not be "clicked" when I press the bottom right corner. 

I couldn't do the "right click" now.

This is awkward.

I know that in System Preference -> TrackPad, I could set the "Tap to click", but then I couldn't use the three fingers swipe to toggle different screens.

Any idea to fix it?
This video recommends resetting the SMC:


Turn off your computer.
Plug in the MagSafe adapter.
Press Shift-Option-Control, on the left side of the keyboard, and the power button, at the same time and hold it for 5 seconds.
Let go of all the buttons.
Turn your computer back on with the power button.


For more information on the SMC reset see this Apple support article