Core/Spells: Replaced assert with startup error log

Port From (https://github.com/TrinityCore/TrinityCore/commit/8043b71708e2efd380c7a1f6a738a1e9e497706d)

Source/Game/Spells/Auras/Aura.cs

@@ -2675,6 +2675,8 @@ namespace Game.Spells
             return aura;
         }
 
+        public List<AuraScript> GetLoadedScripts() { return m_loadedScripts; }
+
         #region Fields
         List<AuraScript> m_loadedScripts = new();
         SpellInfo m_spellInfo;

Source/Game/Spells/Auras/AuraEffect.cs

@@ -334,6 +334,29 @@ namespace Game.Spells
                     break;
             }
             GetBase().CallScriptEffectCalcSpellModHandlers(this, ref m_spellmod);
+
+            // validate modifier
+            if (m_spellmod != null)
+            {
+                bool isValid = true;
+                bool logErrors = GetBase().GetLoadedScripts().Any(script => script.DoEffectCalcSpellMod.Count > 0);
+                if (m_spellmod.op >= SpellModOp.Max)
+                {
+                    isValid = false;
+                    if (logErrors)
+                        Log.outError(LogFilter.Spells, $"Aura script for spell id {GetId()} created invalid spell modifier op {m_spellmod.op}");
+                }
+
+                if (m_spellmod.type >= SpellModType.End)
+                {
+                    isValid = false;
+                    if (logErrors)
+                        Log.outError(LogFilter.Spells, $"Aura script for spell id {GetId()} created invalid spell modifier type {m_spellmod.type}");
+                }
+
+                if (!isValid)
+                    m_spellmod = null;
+            }
         }
         public void ChangeAmount(int newAmount, bool mark = true, bool onStackOrReapply = false, AuraEffect triggeredBy = null)
         {

Source/Game/Spells/SpellManager.cs

@@ -2222,6 +2222,8 @@ namespace Game.Entities
                     case AuraType.AddPctModifierBySpellLabel:
                     case AuraType.AddFlatModifierBySpellLabel:
                         Cypher.Assert(effect.EffectMiscValue[0] < (int)SpellModOp.Max, $"MAX_SPELLMOD must be at least {effect.EffectMiscValue[0] + 1}");
+                        if (effect.EffectMiscValue[0] >= (int)SpellModOp.Max)                       
+                            Log.outError(LogFilter.ServerLoading, $"Invalid spell modifier type {effect.EffectMiscValue[0]} found on spell {effect.SpellID} effect index {effect.EffectIndex}, consider increasing MAX_SPELLMOD");
                         break;
                     default:
                         break;