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