Final Fantasy XIV has been struggling to keep up with its rapidly expanding popularity in recent months, and the devs are making some more changes to address the issues. But that's going to take some work, and thus servers are coming down for an extended maintenance period this evening. Nothing to do but wait for them to come back up, sadly.
FFXIV servers will go down across North America and Europe starting at 7pm PDT / 10pm EDT on September 27 (that's today), or 3am BST on September 28 (that's tomorrow). The companion app and Lodestone site will also be unavailable during maintenance - those will come back up on September 28 at midnight PDT / 3am EDT / 8am BST.
Access to FFXIV itself will be restored on September 28 at 3am PDT / 6am EDT / 11am BST. The devs say that during this maintenance work, they will be "implementing measures to address heavy server stress loads based on the result from the public server stress test we have held the other day".
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