Go to Window>Customization>Customize menus. A "menus" window will open up, where you can customize your menus and submenus. Select M_EDITOR if it's not already selected and look at the list. If Submenu Character is missing I think you may have removed it by accident or have a corrupted prefs file... in which case quit C4D and look in your Maxon>Cinema 4D Rxx >prefs folder, and if there is a c4d_M_EDITOR.res file remove it and restart Cinema. That should force it to revert to the default menu with all of its submenus.