1, the remaining memory space of the mobile phone system is insufficient: this means that the memory space of the mobile phone is not enough to accommodate new applications. The memory of the mobile phone is limited, and it will occupy some memory when installing new applications or games. If the memory of the mobile phone has been filled with other applications or data, there is not enough space to install new applications.
In this case, you can free up more space by uninstalling unnecessary applications or games or moving some data and applications to the SD card.
2. Not all officially signed jar and APK are checked: in Android development, applications are usually distributed and installed in the form of APK(Android package) files. The APK file contains all the code and resources of the application. In some cases, the application also contains one or more jar files, which contain the library code of the application.
When packaging formally signed APK, you must ensure that all jar files and APK files are signed correctly. If some files are not signed, the Android system will detect inconsistent signatures during installation and refuse to install.
3. The signatures of the same package name APK are inconsistent: in the Android system, each application has a unique package name. The package name is used to identify and distinguish different applications in the system.
If an application with the same package name as the factory test 1.5.APK has been installed on the mobile phone before, and the signature of the application is inconsistent with that of the factory test 1.5.APK, then the Android system will refuse to install a new apk, because the system thinks it is a different application and there are security risks.
In this case, you can solve the problem by uninstalling the old application or ensuring that the new APK has the same signature as the old application.