Quoted from Kristin Reilly:
As some of you have correctly guessed, the maintenance we underwent today was to address the duplication bug that's been plaguing us. We have successfully issued a server side patch today. That means we were able to patch this issue WITHOUT forcing our users to incur a huge file download. Yay! It also means we've fixed this issue.
Why didn't we announce sooner the servers were going down? And why didn't we say we were patching the dupe bug?
We purposely didn't post the server status message until an hour before the downtime and updated the launcher files with only a few hours notice on purpose. We didn't want to let everyone know we were patching the dupe bug and cause dupers to create even MORE duped items. While I understand this caused an inconvenience for some users, please realize we are, for the most part, incredibly deliberate in the majority of our actions.
I want to thank all of our community members that alerted us to this bug (past and present) and those that have helped us track down dupers.
Thank you everyone who's stuck with us and supported us, we know it wasn't fun, and it's definitely been a learning experience for us.
Again, the correct way to report bugs you find to us is to email them into firstname.lastname@example.org.