I will follow up your support request here: Can you please let me know the following:
1. For which platform are you building your project (Linux Desktop or a mobile device like Android or iOS)?
2. If a mobile device, can you have a look inside the directory “<V-Play-Root>/5.5/android-xyz/qml/VPlayPlugins/facebook/” and give us a short listing of the included files (if you’re building for iOS please replace the android-xyz with ios).