Could not initialize the tracker after building exe file for PC

Hi everyone, Very new to this, trying to use Unity with Vuforia to make a very simple AR model following the tutorial here: https://blogs.windows.com/buildingapps/2016/10/12/how-to-develop-augmented-reality-apps-with-vuforia-for-windows-10/ It works perfectly in Unity, but when I build it for a PC in order to make an .exe file, I have major issues where the following error messages appear: "could not initialize the tracker" and "dataset target_images could not be loaded and cannot be activated" I am using Unity 5.6.1 and Vuforia SDK 6.2.10 It's doing my head in. Can anyone please help? I would massively appreciate your assistance. Gilbert