Learning Hebrew? Parsing the Optative Middle? Discerning the difference between Hittite and Israelite covenants? Deciphering the number of the beast while calculating the weeks left until Christ's return? No, the greatest problem in biblical hermeneutics is a philosophical one: on what basis do we believe that God (incomprehensible, infinite, transcendent, other, holy) communicates something which can be understood by humanity (fallible, finite, familiar, frail, feckless)?
Another way of stating the problem is to observe the chasm between God and humanity and asking how does communication take place across it? One way to think of the chasm could be to think of the difference between an ant and a computer, or the impenetrability of a wall of lead, or a plankton at the bottom of the sea and an eagle soaring above a mountain: communication is impossible across any one of these chasms. It is even more so between God and humanity.
Bringing this back to our understanding of Scripture in relation to the 'Word of God' or God communicating to humanity, we are entitled to ask, is Scripture really the Word of God, or simply humanity's best attempt from its side of the chasm to bridge the divide?