Hi Umberto and kurione_14
Because I'm not good at English, might be confusing content.
I have exactly the same trouble situation.
There is an anxious point one, because Mr. Umberto write "Maybe there's an issue with the FSX Japanese version",
In FSX Japanese version, there is a place that using 2-byte(multiple-byte) characters in the various configuration files.
(Ex.At 1-byte(single-byte) characters, "1. Voice of English man." At 2-byte(multiple-byte) characters, "1.英国人男性の声".
Both characters is same mean.)
So, If couatl.exe read data from such as configulation file(configuration file include 2-byte characters ),
Can you verify couatl.exe will work?