Fine, this time I actually built it. Promise.

src/server/game/Scripting/ScriptMgr.cpp

@@ -1605,7 +1605,7 @@ uint32 ScriptMgr::GetDialogStatus(Player* player, Creature* creature)
 
 bool ScriptMgr::CanSpawn(ObjectGuid::LowType spawnId, uint32 entry, CreatureTemplate const* actTemplate, CreatureData const* cData, Map const* map)
 {
-    ASSERT(cTemplate);
+    ASSERT(actTemplate);
 
     CreatureTemplate const* baseTemplate = sObjectMgr->GetCreatureTemplate(entry);
     GET_SCRIPT_RET(CreatureScript, baseTemplate->ScriptID, tmpscript, true);