Yes, the site was down. Please try after sometime.
I start the test, the clock is ticking and I can try anything!!!
before starting the exam you should make sure everything is ready and working fine, which includes acme site log in and check for workitems those details.
Please try after some time or make all the framework ready and then you can log in to acme and add selectors and other details as required.
let us know if this helps,
Now the certification platform is not working either, I think UIPath should guarantee access to their pages.