It's a multi-server thing, specifically involving Japanese+Unicode.
The first and last characters of the string are ***, is my guess.
Quote:
Aンバス1章とて いきませんか?サチコ参照で募集中ですー@3ンマュセンマュセヤニテカ.l~アリT~l~lヤニエチ漏6
^ The first character ”ア” is truncated to the English token "A".
The intended last part of the string is supposed to be "@3/6", but the "/" is being interpreted as "ンマュセンマュセヤニテカ.l~アリT~l~lヤニエチ漏".
So the 0th character and the n-1th character seem to be ***, or maybe the nth character instead. It's not a game issue, it's a problem with FFXIAH's/Guildwork's string encoding that broke after the update I think.
EDIT: If SE changed the packet structure and the client code for reading plaintext strings then yeah this could be a Windower issue. If Guildwork is stuck with an earlier Windower client, then the shouts are gonna be borked until something is changed.