Windows 8.1, I did a clean reinstall and installed Pendragon's Tiara and newest Abyss today, and my client crashes before Pleione engine loads completely. Any insight on it, or do you need more info?
If you're using the current abyss, I don't feel this is it, as it seems other mods related. For sure, you want to double check Blade's first page and make sure you covered all steps he mentions there...
Most likely Causes:
Outdated xml files. As of 204a, of the files currently... This isn't an issue.
Corrupted packs, caused by DataPacker using outdated xml files. This happens when people forget to unpack the mods/remove them from their packs. They remove the data folder and try to run DataPacker, but then DataPacker has nothing to work with to remove the mods... You then have corrupted packs and need to get new ones, or pray that you can undelete that data folder and then remove them from your packs. If this works, then once the packs have had the mods removed you can then rid yourself of that data folder.
There was a windows update/program side/client update of sorts. This means that you have to remove abyss and disable mods (rename your data folder and/or remove them via DataPacker). Boot the client normally until you get to the login screen, after making sure you have the right ijl15.dll (ijl15.dat renamed to .dll -- aka the original file). For additional info on this please reference my guide in my sig which mentions the pitfalls and things to be aware of. It also mentions the past few things there.