Hi,
I'm having a similar problem. See my post here
Sudden Voce Chorus-Vibrato Authorization Error ...
... btw, I'm running PT 9.0.6 with absolutely no problems until this issue occurred. I suspect the specific version hasn't anything to do with it, unless it's an ongoing bug in all versions of PT9.
As you can read in my thread referenced above, I tried all the standard "fixes" and nothing has worked so far.
I did not try deleting the PT databases. It would be great if someone more knowledgeable about the low-level functions of Pro Tools would chime in.
Maybe together we can find a solution ...
Cheers,
-Wayne