Update 2: Amazon have confirmed that no characters are actually missing and will be present when the issues are fixed.

We have confirmed that no characters are missing. All characters created will be present upon logging in.

— Lost Ark (@playlostark) February 11, 2022

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Update: servers are now offline. We will update this post as new official statements come in.

Many head start players are experiencing their characters missing on their servers and are unable to enter the server if it has been locked for new character creation, and Amazon responded that they're investigating, and taking servers offline.

We have received your reports that characters are missing, we are taking servers offline to get this resolved.

We apologize for the further delay, we’ll provide updates as soon as possible.

— Lost Ark (@playlostark) February 11, 2022

Source: News Latest Topics https://www.icy-veins.com/forums/topic/64210-lost-ark-missing-characters-official-amazon-response/