Having tried the few suggestions that were understandable (uninstall and reinstall - change screen resolution), none of which made any difference. I have spent quite a lot of money buying games from Big Fish Games, and as long as I was a member, my games worked just fine. It was not very helpful, as it just reeled off a whole lot of highly technical stuff that I had no clue about (I play computer games, I am not a computer technician/expert). I went to the Big Fish Games site, and searched their 'Help' option. This was a game I'd played many times, and was a favourite, but now it wouldn't work.
Everything seemed fine, until I tried to play one of the games I'd bought. Recently however, the games have not been worth playing, and I decided to end my membership. I was a Big Fish Games subscriber for several years, and ended up with quite a large collection of games, all paid for with my subscription payments.