If a menu command is grayed-out (inaccessible; cannot be clicked) in LIMS-plus v5, it is because the logged-in user has not been given a Security Role with the related permission(s) assigned to it. (See the How do I change a staff member's Security Roles in LIMS-plus v5? topic for more information on how to assign Security Roles.)
Of note, it is usually the command or feature's View permission that controls whether or not the command is available on the menu. For example, a user not assigned the Admin - Analytical Module - View permission will see a grayed-out Analytical Module command on the Admin menu (and will not be able to access the Analytical Module screen).