After replacing the uk.dic and the user.dic and this not helping, I completely reinstalled the client, wiped out everything that existed before, and made the password on the ID file more complicated.
My user has been off for a while, came in today, worked for an hour and then crashed with exactly the same fatal thread.
Only having part of the NSD I really can’t tell too much. But it would appear that a 3rd party app may be a fault here. If there is an AV running on this client try disabling it for a day or so and see if that helps. Also check the OS event logs to see if you can determine a problem outside of Notes.