Is there anything different from the guide that you did? Because I'm following the guide exactly (afaik) and I'm unable to get WUP installer to install it
The only thing I did differently from the guide is that I went through both the USen and JPja audio folders, listened to all the recorded dialogue for each cutscene, and assembled a combination of the two according to personal taste. It installed just fine and seems to run without issue (though with my luck it'll crash somewhere because I missed a file or something).
If you just copied and renamed the JPja audio folder, check the rest of your process, because the guide has worked as written for others.