If you upgraded to Pd-extended 0.40.3, and you get a lot of messages like this in your Pd window: :

  cyclone: can't load library
  zexy: can't load library
  cxc: can't load library
  ext13: can't load library

Then, you need to update your preferences. The default preferences are now embedded in the app, so you can just delete your own preferences file and Pd-extended will use the embedded preferences. You can find out where the preference file is on your Operating System by checking the pdsettings FAQ entry

If you want to keep your preferences file, then you need to add libdir as the first library loaded.