Same for me, just crashes on start-up every time.
To elaborate on this, upon pasting the 6 files included in Abyss.rar into the main Mabinogi directory (and overwriting the default ijl15.dll), I run the HSLaunch.exe, open Mabinogi.exe, and press "Start Game'. Upon which, Client.exe momentarily appears in Task Manager -> Details, but the HShield logo doesn't appear in the bottom right corner, and Client.exe is gone from Task Manager. Have I missed any steps in properly accommodating Abyss into the clean Mabinogi?
There is a separate thread with a R203 to R204 data folder patch, which I've already included, and I've also changed Debug=0 within Abyss.ini.
EDIT: I am running Windows 8.1. Also, running the game via the modified client launcher included in this thread does make the HShield logo appear in the bottom right corner, but Client.exe still disappears from Task Manager within a few seconds.