Hi,
I just bought a few plugs here for PT 9 HD running on OS 10.8.4. They all installed fine except the Master Comp, which required the input of the user name and license key to authorize. When I enter the user name that was sent to me in the registration, that is in my profile on the PSP site, it won't accept it and says it's invalid. What's going on? PSP Support has sent me very unhelpful emails saying to try to authorize the Master Comp in Garageband, which I don't use. I bought it, but I don't see the Master Comp coming up anywhere as an available plugin. I would really appreciate some help here. Thanks - Steve

Please install both AudioUnit and RTAS version of the plug-in.
Then open a MasterComp in the GarageBand and enter your authorization details.
There is a nice tutorial which shows how to get access to the plug-in in the GB
http://www.sfxmachine.com/garageband.html