1) The phone has insufficient memory.

2) Mobile phone settings do not allow the installation of applications from unknown sources.

①Click Settings.

②Click other advanced settings.

③Click Security and Privacy.

④ Check to allow installation of applications from unknown sources.

3) The network is unstable and the installation package is damaged during the download process. It is recommended to download and install again.

4) Change the download source and download from the official website.