I think some issue with short url he used. Check your link and correct.
What's the point did you register just to post this link, it's suspicious you know that this is a Cryptocurrency forum and what you post is not a Cryptocurrency related subject and to think that you pay just to escape from newbie jail, there's a hidden on your link and since you got flag your account is now disposal and useless.
Link he provide redirect to suspicious link, or it may look like he used a short link which redirect to many other pages and then open original page. I search and found some short url provider use cpm service like infolink to make money. Better to delete these kind of post.