I am not sure if I should contact Coursera team for this. I am doing the Neural Networks and Deep Learning course. I can not open the Week 1 quiz. I took it once and failed. I extended my course completion date and want to re-take the week 1 quiz. When I click on the link, I see an expanding circle animation and the quiz never opens up.
As Gent mentioned, this is a Coursera related issue.
Try clearing your browser history and cache, maybe even try using a different browser, but if the issue remains, please reach out to Coursera support (via chat or email) for this. Thanks!