When using the software this weekend, I thought I discovered a fault in one of the libraries. By some misunderstanding, I got the impression that one pin on the Zilog Z80 processor (HALT on pin 18) is defined as an output instead of an input. (Yes, it is an Output). Using the library editor, it was easy to change the properties of the pin, but I was not able to update the library, since it is in the C:\Program Files... path.
Even with changing the administrator rights of the folder in Windows, I still got the error message that I could not save the updated library because I did not have write priviliges to that folder.
I guess if I keep all the libraries in the User\documents.... path, this would not be a problem, but since the installation process puts them in the C:\Program Files\KiCad....... the correct privilegies should be set.