I am experiencing this issue as well but slightly different. I was able to play the entire day with no problems with chat. However, after setting up a private shop and confirming 'start sale' I encountered this issue. The first occurrence of this error is after I used global chat (!) and the following message appeared. I have tried logging out and restarting the game but the message still persists. This error message is displayed after using the [ All, !, and + ] channels. The message is not displayed if using the [#, ", @, and $] channels.
Do you have any further information about when the next updater will be implemented? I agree, along with many users, that this server must not have this problem with the updater being detected as "Trojan:Win32/Pocyx.F!plock"