Mage Armor still (despite, by my count, three attempts at fixing?) still stacks with armor.

Tasha's Hideous Laughter automatically works on someone (no saving throw involved) if they have Protection from Evil up.

Howland Mage Armor still (despite, by my count, three attempts at fixing?) still stacks with armor.

Try this:

#include "nw_i0_spells"
#include "x2_inc_spellhook"
void main()
{
    if(!X2PreSpellCastCode()) return;
    object oTarget = GetSpellTargetObject();
    float fDuration = HoursToSeconds(GetCasterLevel(OBJECT_SELF));
    if(GetMetaMagicFeat() == METAMAGIC_EXTEND) fDuration *= 2;
    SignalEvent(oTarget, EventSpellCastAt(OBJECT_SELF, SPELL_MAGE_ARMOR, FALSE));
    effect eAC = EffectACIncrease(4, AC_ARMOUR_ENCHANTMENT_BONUS);
    effect eDur = EffectVisualEffect(VFX_DUR_CESSATE_POSITIVE);
    effect eLink = EffectLinkEffects(eAC, eDur);
    effect eVis = EffectVisualEffect(VFX_IMP_AC_BONUS);
    RemoveEffectsFromSpell(oTarget, SPELL_MAGE_ARMOR);
    if(GetItemACValue(GetItemInSlot(INVENTORY_SLOT_CHEST, oTarget)) == 0)
    {
        ApplyEffectToObject(DURATION_TYPE_TEMPORARY, eLink, oTarget, fDuration);
        ApplyEffectToObject(DURATION_TYPE_INSTANT, eVis, oTarget);
    }
    else
        ApplyEffectToObject(DURATION_TYPE_INSTANT, eVis, oTarget);
}

I didn't test it though.

We haven't once attempted to fix it.

Will that code prevent you from casting mage armor and then putting on heavy armor and getting the additional AC?

Arkov Will that code prevent you from casting mage armor and then putting on heavy armor and getting the additional AC?

The script just checks to make sure that the AC of the armor that you're wearing at the time the spell is cast is zero, before it applies the AC bonus. As far as I understand it, it's not accounting for the case where you put on heavy armor after the spell has been cast.