If you are on a legal copy of AC a steam integry check always does the job especially in restoring messed up files. I´ve had the same issues years ago and it worked. In general I don´t like your approach to create a new profile here and ask for a link to official paid content.
Believe it or not, I'm not that new here but was only a reader in this thread. In general what I don't like about you, is your attitude and aproach to make it look like I'm trying to get the track for free here... Believe me I don't need it that much. ;-)
For your information, the problem is, that the game crashes when I load my KS Nordschleife and change the PP Filter.
If I use a modded layout with modded textures, everything is fine and the game is not crashing.
I uninstalled and newly installed CSP (from V0.1.46 till V0.1.50), tried to "originalize" the Folder of "nordschleife" in ks_nordschleife as good as possible including a filescan and restore via Steam. Nothing worked.
I did not want to drive to my company today (on a sunday) and take the original file from my unmodded version on the PC there, which I did meanwhile btw...
If you like to, have a look at my Steam account
https://steamcommunity.com/profiles/76561198035088024/ to make sure im not trying to scrounge anything here. I really don't have to. ;-)
Have a nice evening mate.