For some reason sometimes when I have a nautilus window open, then switch to a different window, when I click on the nautilus icon in the Unity bar, it opens a new nautilus window instead of the existing one. Yes the old window is still there, if I minimize the fullscreen window it reveals both of them, and the nautilus icon has two ticks.
I think this question's been asked already, but there's no solutions.
Ubuntu – How to make the nautilus icon open the existing window instead of a new one
nautilusunity
Best Answer
I watched a video and it says that the problem can be solved by NOT clicking on it , instead you just scroll your mouse over the Files icon . It worked for me.