Regulations in that part of the forest are rather clear: you have to stay on the official paths yet I just can't see the path you mention north of this marker: https://www.mapillary.com/app/?lat=50.7586522&lng=4.4340916999722&z=17&pKey=267159022235380&focus=photo&x=0.7662206215065742&y=0.5907389585888908&zoom=0.05212714870312692