I had a licensed version of Kontakt 7, and everything was working fine. Suddenly, I couldn't play my libraries because it reverted to DEMO MODE, saying I had to activate it. When I tried entering my serial number, I got an error message saying "invalid serial number". Since I'm in the middle of a music project and can't wait for NI Support, I bought a SECOND license, which registered successfully. So I uninstalled Kontakt 7, but when I tried to install it from Native Access, I got another error message saying "installation failed. Review your preferences." So I uninstalled and reinstalled Native Access with the default preferences. There was no difference. Now my TWO serial numbers show up in my "Registered Serial Numbers" list, but I can't install Kontakt 7.
Can someone PLEASE HELP???