what exactly does not work? What you did to set custom menu? Did you created menu first and then did you set it as main menu under Appearance > Menus > Manage locations section? Please explain.
create the custom menu just for a page apart have the main menu, then on the gallery page I want to use the new menu, you select where it says Custom menu, upgrade, but the upgrade does not show the new menu, only the menu appears principal.
now upgrade theme 10 to 12.5 when finish, send image for example
Please send us private message with dashboard access and details like for which page you set this custom menu and it does not work and we will have a look on it.
Comments
what exactly does not work? What you did to set custom menu? Did you created menu first and then did you set it as main menu under Appearance > Menus > Manage locations section? Please explain.
P.S. More details about WP custom menus you can find on https://en.support.wordpress.com/menus/
Thanks!