I followed the instructions in Burianek's sticky about sound modification; Here's what I did:
1) Identify undesired sound effects in the 440001.pck file.
2) set the duration to 001 milliseconds in 00044.xml.
3) save and zip to 00044.xml.gz.
4) crypt to 00044.pck.
5) x2build to tranquility.dat and tranquility.cat.
6) copy to x2 root directory and rename 06.dat/06.cat (05 is removing the "modified" tag).
7) Run game and learn that nothing has changed.
The game is running in modified mode since I have access to the script editor.
I tried putting tranquility.dat/cat in the mods folder and activating them, but to no avail.
What am I doing wrong?
