I have uBlock Origin and it worked fine for a while, but for the last couple of days I am being prevented access to more and more Web pages. I even tried to disable the blocker and I still see this when I go to the page:
I don't know about UBlock, but I have been using ABP(Ad Block Plus), for years, with minimal "inconvenience". It's free, and easy to disable/re-enable if I go to a site that won't respond with ABP active. Try it, it's free and easy.
Just as clarification, it is the WEBSITE that is blocking you, not the ad blocker. If you read that notice, the website wants you to turn off your ad blocker so you are forced to see their advertising.
When you get the information that you require
to allow a website to show ads when you visit,
the ads are only shown at the beginning, not
while you are playing a game, I do the same for
a crossword area in a newspaper.