Can't log in - "connection timed out" - after logging out during visual desync

What I did: I (Player_Name) was playing last night (around Aug 10 1 am UTC) killing skeletons in the deep wilderness. I experienced heavy visual desync and wanted to relog to "fix" it, so I logged out and tried to log back in.

What I expected to happen: I would log back in.

What actually happened: Client hangs on the login screen and eventually gives up saying "connection timed out". Mobile doesn't work either. Alt accounts can log in fine, and show Player_Name as logged out. I went to sleep and wanted to try again just now (nearly 12 h later), but the situation hasn't changed: client is still saying "connection timed out" for only this account.

IDs of related NPCs/items:

2009-era source (if relevant):

Screenshots or video:

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