This question is very similar but slightly different. I followed the steps on the other question ( https://answers.presonus.com/35108/studio-one-4-and-piapro-studio
) However, after following the activation steps on the knowledge base I still can't get it to search for Piapro Studio VST plugin. (Went to Menu, Studio One>activate>Use existing Key>Studio one 4 OEM Crypton> Ok> Activate> Success! Closed, restarted) In the menu, Studio one>Options>locations> X doesn't show VST plugin's as options. I also bought the V4X bundle which included Studio one 3 APE (When registering it Studio 4 showed up) Downloaded S1 4, so it should be 64 bit. Reset the application. Did a full uninstall and reinstall of the program, reactivated, still unable to find Piapro plugin.