In case you guys experienced a domain not resolving error or a typical parked domain page, that was due to a nameserver update I did, actually a nameserver update I forgot to do after changing my server's main domain name.
I was so sure I had done so, that it totally escaped my mind.
Good thing I noticed the downtime within an hour and performed the fixes, so you may have not noticed it at all.
That's all! Take care!