On map frozen landscape (ice) there's an ugly scar feature with an ice bridge, if you step off into the skinny side you get stuck. There are two ice bridges (the solid one has fatter exits so no problem), the raised one you can see under is the one I mean.
Also, does the RF for the knives just not work? I swear there were times during the campaign with the Monomolecular Knife when I had either function (stab/throw) engaged and nothing; so I tried to get a RF stab/throw in skirmish mode with the combat knife, monomolecular knife and kerrblade(just the single stab function) and it was a no go there too.