We check this website, now jcsdk12.org is up and dont blocked for our system and other users of the Internet.
So, answer to question: Is jcsdk12 Down Right Now? - NO! jcsdk12 is up!
If you have problem with access to site jcsdk12, and domain jcsdk12.org is not avalible.
Clear browser cache and/or try other web browser
(Chrome, Firefox or Safari).