unable to edit menus

[mosaic2s]

I have installed QCAD from ubuntu software center. Unable to locate it in the menu. Presently using terminal to access the program.
Went to applications, right click mouse - clicked on edit menus - nothing happened.
Went to preferences - clicked on Main menu - nothing happened.

What can be done.

[mosaic2s]

used root privileges to allow read and write permissions to the config menu directory and the files in that folder.
menu can be edited now.