Impossible to register

[Batata45]

Hello, after trying to help Bojan who had difficulties with registering an account on this forum, I found what seems to be a bug. I asked him what was the matter, and he tried to explain me with his (broken) english. He asked me to register for him, then I got the same issue as him (see the screenshot below), so I figured this wasn't from our computers but from the website itself. 

The error message says this: "Error for site owner: invalid site key"