There are generally the following reasons: 1. The general software version is incompatible with the mobile phone system. Update your system through System Upgrade in Settings. 2, the phone memory is insufficient, try to clean up the memory. 3. The application package file is damaged, so it can be uninstalled and downloaded again.

Smart Primary and Secondary School is an educational learning app that can help primary and secondary school students develop in an all-round way. Users can see all the auxiliary learning video resources in the school curriculum through smart primary and secondary schools, and provide long and thin course textbooks to explain the important and difficult points and other high-quality special education for free.