As I've mentioned, this is not an issue that other users are seeing, which means that it's the result of some combination of issues on your end.
Have you tried adding P+ to a blank project? If that gives you an error, then it might that you've put the plugin in the wrong part of your project directory.
If it works in a blank project but not in your main project, then it could be any number of issues. In a very large project it could be that there isn't enough room in a bank to add the plugin; or if you've done any engine edits then those can create conflicts.
Without a more detailed description of your setup, it's impossible to troubleshoot.