Menus that pull in across different pages require editing separately from the page you may have seen them on.
To do this you need to access the .php file. This can be done through - Appearance - Editor on the left-hand menu at the back end of WordPress.
It's always safest to try any changes on the STAGING and then, if they work, repeat on the LIVE. For big alterations, make a back-up of the STAGING before you start.
1) Locate the menu you want to change. The above is the Header, so open Header.php
2) Locate the text you want to change (CTRL+F 'masters')
3) Edit this text (add apostrophe to masters in all visible areas)
Do not edit the text in areas that relate to the menu file <?php wp_nav_menu(array('theme_location'=>'general_masters', 'container_class' => 'single-list')); ?>
4) Click 'update file' in the blue box below the content areas box.
5) Check this has worked across multiple pages that use the menu
Copyright text needs to be updated at the start of every year.
To do this:
Open 'Site Wide Options' from the dashboard left menu and then alter the date in 'Legal Text' field.