diff --git a/RootDesk/MyDesk/CombatMonster.codeblock b/RootDesk/MyDesk/CombatMonster.codeblock
index 5417df0..1989060 100644
--- a/RootDesk/MyDesk/CombatMonster.codeblock
+++ b/RootDesk/MyDesk/CombatMonster.codeblock
@@ -64,4 +64,4 @@
       "EntityEventHandlers": []
     }
   }
-}
\ No newline at end of file
+}
diff --git a/tools/monster/gen-combat-monster.mjs b/tools/monster/gen-combat-monster.mjs
index ecbbe4e..16b33dc 100644
--- a/tools/monster/gen-combat-monster.mjs
+++ b/tools/monster/gen-combat-monster.mjs
@@ -42,10 +42,10 @@ eventId = _TimerService:SetTimerRepeat(reg, 0.1)`),
       EntityEventHandlers: [],
     } },
   };
-  writeFileSync('RootDesk/MyDesk/CombatMonster.codeblock', JSON.stringify(cb, null, 2), 'utf8');
+  writeFileSync('RootDesk/MyDesk/CombatMonster.codeblock', JSON.stringify(cb, null, 2) + '\n', 'utf8');
 }
 
-const isMonster = (e) => (e.componentNames || '').includes('script.Monster');
+const isMonster = (e) => typeof e.componentNames === 'string' && e.componentNames.includes('script.Monster');
 
 function patchMap(nn) {
   const tag = String(nn).padStart(2, '0');
@@ -53,9 +53,13 @@ function patchMap(nn) {
   const map = JSON.parse(readFileSync(file, 'utf8'));
   let count = 0;
   for (const e of map.ContentProto.Entities.filter(isMonster)) {
+    const comps = e.jsonString && e.jsonString['@components'];
+    if (!Array.isArray(comps)) {
+      console.warn(`[gen-combat-monster] entity "${(e.jsonString && e.jsonString.name) || e.path}" has no @components — skipped`);
+      continue;
+    }
     const name = (e.jsonString && e.jsonString.name) || '';
     const enemyId = NAME_TO_ENEMY[name] || DEFAULT_ENEMY;
-    const comps = e.jsonString['@components'];
     e.jsonString['@components'] = comps.filter((c) => c['@type'] !== 'script.CombatMonster');
     e.jsonString['@components'].push({ '@type': 'script.CombatMonster', Enable: true, EnemyId: enemyId });
     const names = (e.componentNames || '').split(',').filter((s) => s && s !== 'script.CombatMonster');