Over the weekend it might have been a struggle to play WoW Classic, or any Blizzard game for that matter. Blizzard's services were disrupted thanks to massive DDoS attacks which hit the servers Saturday and Sunday.
In a blog post on the forums Saturday, Blizzard acknowledged the attacks and committed to clearing the issue as quickly as they could.
It is our top priority to resolve any issues that prevent players from being able to smoothly play World of Warcraft. However, it is the nature of DDoS attacks that players may experience the game becoming unavailable. If you are disconnected or have issues logging in, please be patient and wait a few minutes before trying again.
As of this morning there isn't any indication on the Battle.net launcher these attacks are still ongoing, but it remains to be seen if the company will find themselves hit again. Also, in case you missed it, be sure to check out our WoW Classic review, which is live now.