...

Oh look, another essential server maintenance, another complaint that gametime is being lost from self-entitled players upset that they lost what... an hour of potential gametime, if that?

SE are entitled to take the game offline for maintenance whenever they like, for however long they want. It's in the Terms of Service you agreeded to when you signed up, and you continue to agree to every time you login to the game. It's been like this since the beginning and will always be so.

This particular maintenance was to fix a serious bug that was actually crashing the servers in certain circumstances, among other things. So it's completely essential.