Before purchasing the full version of Kontakt 1, I had installed the demo. Recently, I began getting a "Kontakt Demo Version 30 Day Trial Expired" message when I launch Pro Tools. Subsequently, I'm not able to open any of the Pro Tools sessions in which I had used Kontakt--the full version--as a plugin.
First thing I did was to trash the Kontakt demo files on my HD, hoping that would elimate the problem. No such luck. I've considered re-installing my full, registered version of Kontakt--wiping the slate clean, as it were--but I'm still hopeful that someone here might have a simpler or less drastic solution.