Same here. I started getting that message a week or two ago. As far as I know I do allow cookies and did not change anything. I used to be able to enter.
Hey arrtup3 - I went back to those ET sweeps and tried to enter again and I got a message that I was already entered so apparently it doesn't matter that the page has a redirect loop.
Thanks, delimama66. I didn't know that, so after reading your post, I went back to the one ET sweep I tried to enter and got the already entered message. Then I tried a few I didn't enter (I had given up on them), and got the error message, but I will try to enter the rest anyway.