Last update crashed admin and cart cookies

With this last update, I was unable to log into the admin. It claimed some sort of cookie problem. I tried also adding something to my cart as a guest user, and when I went to view cart, it kept saying there was nothing in my cart.
I went into cpanel file manager and renamed the Oliver plugin folder temporarily in order to disable the plugin, and everything is back to normal, except that I don’t have a POS.