So I was in a conversation with Astraal when I did a safe logout, after that I could not send private messages to him anymore, getting a “Unknown nickname; you haven’t met this person during this session.” message instead:
14:04:28.540 CHAT| < PRIVATE To >[Astraal] ...
14:05:37.303 CHAT| < PRIVATE From>[Astraal] ...
14:05:48.536 CHAT| Disconnect form chat-server (reason 0)
14:05:51.453 CHAT| Connection to chat-server established
14:05:52.291 CHAT| < SYSTEM> Undocking in progress...
14:05:52.374 CHAT| Join channel <#general_ENGLISH>
14:05:57.927 CHAT| < SYSTEM> Unknown nickname; you haven't met this person during this session.
14:06:14.512 CHAT| < SYSTEM> Unknown nickname; you haven't met this person during this session.
14:06:24.147 CHAT| < SYSTEM> Unknown nickname; you haven't met this person during this session.
Yes, I typed the name correctly. And yes, I tried sending private messages to other players that I had not talked to before in that session and it worked fine. The issue was just with the player I had talked to before the safe logout.