Open Terminal Shortcut (cntrl+alt+t) is Not Working - tried few solutions already

1. Hi there, i can`t open the terminal window with the shortcut i have configure.
2. I have followed few guides without success.
3. I have tried:
   
   • Reset to Defaults - reset all shortcuts to default.
   • change the command from "exo-open--launch TerminalEmulator" to "gnome-terminal" - after installing the gnome-terminal.
   • change the command from "exo-open--launch TerminalEmulator" to "rxvt-unicode" - after installing the rxvt-unicode.
   • Create a new shortcut with other "buttons" is working with all the commands above: (cntrl+alt+shift+t) opening new terminal window.
   
   
4. How can i return the shortcut (cntrl+alt+t) to work out ?