The mobile phone system signature failed to obtain the signature correctly. The operation steps are as follows:

1. Check whether the system is an apk with the same package name through adbshellpmlistpackages.

2. You can uninstall apk with the same name through adbshellpmuninstallcom.example.myapplication, and then try again.

3. System signature is a manual system signature operation for unsigned APK files generated by AndroidStudio.