There are places in Farglow that you can not get to (I tried unsuccessfully to jump over the wall in the training grounds area, for example, and part of the river was blocked off, as well), but if your character is within the game area (like on the path from the waterfall) they should not be getting blocked.
Have you gotten to Broken Valley yet, and have you had the same problems there?
Possibly related:
Can't run up any sort of incline, just walk
