Baldur's Gate : The Sword Coast Chronicles : NWN2 Persistent World

I use the energy immune scrolls to block fire damage, but it never work even when the UMD roll is successful. He still receives damage.

Just did a test run with using Energy Immunity scrolls rather than my prepped spells for the UD Pit Fiend fight. Energy Immunity (Fire) worked as intended with scrolls to counter the aura damage. When you use a scroll, do you Right Click -> Energy Immunity -> select Energy Immunity (n) elemental option, or just click the item? The default setting is for Energy Immunity (Acid). If you click the Remove Effects button in your PC tools window, you'll see the actual energy immunities being applied currently:


EDIT: Double checked by passing along scrolls of Energy Immunity to another UMD-focused character to check if that's could be the limitation. Using the right click options should still apply the proper immunities from scroll use to be visible under the RE tab.