Cookies is not defined

Hello,

the plugin does not work for me and shows the following error in the browser console.
What can it be?

Uncaught ReferenceError: Cookies is not defined
at rmp_can_vote (rate-my-post-public.js?ver=2.2.1:423)
at HTMLDocument.<anonymous> (rate-my-post-public.js?ver=2.2.1:8)
at i (jquery.js?ver=1.12.4:2)
at Object.fireWith [as resolveWith] (jquery.js?ver=1.12.4:2)
at Function.ready (jquery.js?ver=1.12.4:2)
at HTMLDocument.K (jquery.js?ver=1.12.4:2)

The page I need help with: [log in to see the link]