Missing CRM Tab in Settings

Here is the WP Debug data:

Fatal error: Uncaught Error: Call to a member function save() on null in /var/www/vhosts/HIDDEN.com/httpdocs/wp-content/plugins/erp/includes/framework/class-settings.php:129 Stack trace: #0 /var/www/vhosts/HIDDEN.com/httpdocs/wp-content/plugins/erp/includes/framework/views/settings-page.php(5): WeDevs\ERP\Framework\ERP_Admin_Settings::output() #1 /var/www/vhosts/HIDDEN.com/httpdocs/wp-content/plugins/erp/includes/class-settings.php(18): include(‘/var/www/vhosts…’) #2 /var/www/vhosts/HIDDEN.com/httpdocs/wp-content/plugins/erp/includes/admin/class-menu.php(56): WeDevs\ERP\Settings->__construct() #3 /var/www/vhosts/HIDDEN.com/httpdocs/wp-includes/class-wp-hook.php(298): WeDevs\ERP\Admin\Admin_Menu->settings_page(”) #4 /var/www/vhosts/HIDDEN.com/httpdocs/wp-includes/class-wp-hook.php(323): WP_Hook->apply_filters(”, Array) #5 /var/www/vhosts/HIDDEN.com/httpdocs/wp-includes/plugin.php(453): WP_Hook->do_action(Array) #6 /var/www/vhosts/HIDDEN.com/httpdocs/wp-adm in /var/www/vhosts/HIDDEN.com/httpdocs/wp-content/plugins/erp/includes/framework/class-settings.php on line 129

I’ve deactivated all other plugins to check for a conflict but there was no change.

I have also deleted and reinstalled the ERP program with no change.

ETA: Also reverted to the Twenty Seventeen theme

Thanks. Those roles are already assigned. Are there particular user capabilities or permissions needed to access the tab? If so, I can add a custom capability in User Role Editor to make it functional.

Thanks