Well, indeed it had to be something else in my setup causing the problem. I recently tried relaunching the game through MO1 again, and I can't see any trace of the original problem. There's been a JIP LN update in the meantime, but I doubt that was the cause. I wouldn't mind not encountering such problem ever again anyways.
Apologies again, since in retrospect this entire thing was a desperate barging in for a solution.
