When your Cocos exported file build id dismatches your Cocos2d-x reader build id, please select the correct reader from this table(you may need to upgrade your Cocos2d-x) and put it into your game project to update your reader:
| cocos-reader | Based on cocos2d-x | Match with Cocos |
|---|---|---|
| Build id 2.0.8.0 | cocos2d-x-3.4beta0 | Cocos 2.1beta For Mac For Windows |