微信小程序后台发送订阅消息 47003？

请求是

{"touser":"o_ast5KGaQqMSP86EHeY4ul5TwHM","data":"{\"character_string1\":{\"value\":\"1610354817196nlr5\"},\"thing3\":{\"value\":\"\"},\"date2\":{\"value\":\"2021-01-11 16:49:53\"},\"thing4\":{}}","miniprogram_state":"developer","template_id":"zDpOMaMoCAvOZ6IMVlovaXHhQTjxSw5dGPTfHrw6Lbo"}

返回

{"errcode":47003,"errmsg":"argument invalid! data.character_string1.value i rid: 5ffc1132-7ea13319-4c59479e"}

参数名全部核对了 都没问题 character_string1 长度17位 不超 还请各位看下是什么问题 谢谢