schoolboy error
noun [ C ] UK uk/ˈskuːl.bɔɪ ˌer.ər/ us/ˈskuːl.bɔɪ ˌer.ɚ/ (US rookie mistake, uk/ˈrʊk.i mɪˌsteɪk/ us/ˈrʊk.i mɪˌsteɪk/)
小学生才犯的错，最基本的错误
a basic mistake, like one that a person with no experience of an activity would make
Sending the wrong message to the wrong group is a schoolboy error you will avoid with the help of our app. 在我们的应用程序帮助下，你可以避免向错误的组发送错误的信息这样的基本错误。