Somehow my top bar in Ubuntu Linux had multiple icons for the same program and I could not remove them. Right clicking did nothing, left clicking started the program, Shift-dragging made duplicates of the icon, Ctrl-dragging did nothing useful.
There is a solution.
Use the Super key (on PC keyboards it is also known as the Windows key) and Alt together, finally Right click on the icon to bring up a menu with “Move” and “Remove from menu”.
Click on “Remove from menu” and the wayward icon disappears.
I hope that helped, if so please feel free to leave me a comment.