can not get rid of Mac Flash Player "Local Storage" popup?!

hi all,

I'm on Mac OSX 10.10.5 and Firefox 63. I'm trying to load a certain page (8-ball pool on www.miniclip.com) I am getting a continuous "Local Storage" pop-up, no matter how many solutions I have tried (and I think  I've pretty much tried them all). I've gone in to Mac Sys Prefs to the Flash Player Pane, have set it to Allow All, have cleared caches, etc. booted, re-booted, re-re-booted, etc. No matter what I do, I cannot get rid of the popup, which won't allow me to continue with the game. BTW, this only happens if I am logged in to my 8-ball pool account. If I try and play as a "guest" - - no popup, try and login? Popup.