Hello edelweis69,
as you were able to play meanwhile, I think that the problem is fixed.
What you can do, when you have such an error is:

Check your internet connection
if it's ok and you can reach other websites:

Check the URL
Refresh the page 
Use a Search engine, Google for example, and search the website. 
Try to access the webpage from a different device. 
Clear your cache and delete cookies. Not only the last 24 hours, but everything.

Wishing you a pleasant day and good games!