Unable to move dock to right side of screen.

For years have place the dock on the right side of screen. All of a sudden the dock disappeared from the right side. Tried moving to the right side using system pref, holding shift and grabbing dock hook (box at break). Using shift and dock hook and moving to right side and dock flashes back and forth between left and right side.

最後更新：2017-08-25 06:41:52