我们是开发者，视频号通过小商店里面的接口获取授权token，一直报错，{"errcode":40001,"errmsg":"invalid credential, access_token is invalid or not latest, could get access_token by getStableAccessToken, more details at https://mmbizurl.cn/s/JtxxFh33r rid: 6670e387-5c1af0ac-75234cfe"}。是什么原因呢？