You should have ALL Kontaktplayers*.dll in that particular VST folder.
Or you re-install the whole lot, or yhou just drag and drop those Kontaktplayers dll's to the folder where the other stuff is located.
Overture just uses one and only one folder (and no subfolders!!!!!) for VST instruments. Under OVerture Preferences check Audio engine, and possibly do another Set Folder (may not be necessary).