OnePiece is absolutely correct here, it's a WInNTSetup issue. I only parse dosnet.inf to create the boot files, but not txtsetup.sif to create $WIN_NT$.~LS folder. Instead the complete folder is copied. While this is of course not the right solution, it much faster. But It only works flawless as long no files are renamed or new created during $WIN_NT$.~LS population. And so it always was with official and unchanged sources. Well, I won't change that anymore, but adding a small check for these 6 files shouldn't be a problem.