Gold star goes to garynorman.
Found it was only sticking at 50% when loading on medium pins, so went with a possible rogue pin solution.
Currently only setting 1 of each difficulty to so all green pins are so far labelled easy1 medium2 difficult 3
Noticed on Hole 2 were labelled easy1, medium3, difficult4 - the clues are starting to point to a rogue Hole 2 pin.... so where is it?
Well searched everywhere where id expect it may be but no visual signs of it, and if anyone has a better way to find it then please let me know as the way I found it is quite long winded but my method is as follows:
Having built the course, navigate to the course folder, and then right click on the .description file and open with Word. Press Ctrl+F and search for the term "pins"
Click the checkbox for highlight found items.
Use the highlight button if you have it on your tool bar to highlight the Pins keyword youve found.
Now everything after that "pins" word is the hole index (Hole 1 is Hole Index 0), difficulty, and x, y z coordinates for all of the pins youve planted
So I knew it was Hole 2 where I had a rogue pin, so Ctrl+F again, and this time search for "holeindex":1
Again make sure the checkbox for highlight all terms found is checked
Use your highlighter pen icon once the search is complete to highlight all your now shown Hole 2 pins.
Now by looking at the x y z coordinates of the pins for the hole they should all be pretty close, so any rogue pin which you havent been able to visually see near you "proper" pins will be vastly different.
Sure enough I had a pin with a hugely different z coordinate - so I now know the location of my rogue pin.
Easiest way I found to then navigate to that position, is to then simply use the human height indicator, or create a small in game asset, a cube for instance, and then set its x y z coordinate of your rogue pin.
Your asset will then move off to the rogue pins location, and its a simple matter of double clicking on that item in your heirachy and you will be magically transported to the rogue pins location and remove
Make sure you exit word without saving
Id say simple as that, and it does indeed sound more complicated than it is. However the ,description file is very handy for find locations of all your tees, pins and shot points should something go awry.
Now hopefully cue someone to tell me theres a simple search function in unity/cf to allow me to instantly navigate to various assets such as pins, shot points etc etc