Please be aware that SLP latest version requires the ENHANCED LEGACY add-ons to be downloaded anew from your account, they will be updated to 4.6.4 and will not work if you do not update them.
Are you using English language on your site?
Just so you know all the Enhanced Legacy add-ons are replaced by Experience Add-on. See the comparison here
You would need to be using WordPress 4.4 at a minimum. Past purchases qualify you for discounts depending on when you bought them, or if you take the hosting survey you may receive a deeper discount for any add-on of your choice, Power, Experience or Premier..