I've found this can be a very common problem with Golden Bear Challenge.
If you find courses or golfers not showing in the game, the following will fix the issue:
Both the Courses and Golfers folders are inside the Golden Bear Challenge Data folder.
Right click on the course or golfer file in your Golden Bear Challenge install that is not showing.
Select Properites
On the General tab, click Advanced
Check the box File is ready for archiving
If this box is not checked, the course or golfer will not show in the game.