I have never encountered such a situation. Maybe the directory is not installed correctly? Check whether it should be in the plug-in of the installation directory. X:\ Premiere \ plugs \, 1.5 I can't remember clearly, if it is Premiere pro 2.0.
Special effects should be installed under X:\ Premiere \ plugs \ XXX \.
I can't remember the names of two folders in the plugin. You can drop it into any folder, but you can't drop it directly into X:\Premiere\Plug-ins\