I’ve been signed-out all of a sudden! I tried logging back in, but the password didn’t seem to work! Then, I requested a password-change more than once, and received no single email so far! Is there any problems in the server?^_^"
Update: Apparently, I forgot that I had registered via my Facebook account. Thus, I tried to enter using it, and it worked! My only notion here is that the website must tell me that my e-mail has no account to request password-changes.