1, connect the computer in storage mode or use Root.

The explorer found it. The android_secure folder in the SD card directory should contain a smdl2tmp 1.asec, or a file with other names. In short, it is obviously different from the normal program naming format. Please delete it, and then try to install the software again.

2. If the installation of the application prompt on the PC fails, please check whether the USB driver corresponding to the Android phone is installed first. Generally, using 9 1 mobile assistant or pea clip will automatically help you install the mobile phone driver;

3. View phone settings-Applications-Unknown source

Check or not, otherwise some applications not provided by the electronic market will not be installed;

4. Use the system's own program management to check the programs on the SD card. Some programs don't actually have colored icons. It turns out that these softwares without icons are at work. These software without icons are incomplete software data that have not been installed or uninstalled correctly before. If you install them again, you will report an error. Uninstall them with the software management that comes with the system, and then install the software without making mistakes.

5. Just delete/mnt/secure/asec/smdl2tmp1.asec.

(In drive mode: removable disk/. Android _ secure/smdl2tmp1.asec), and then install;

6. When upgrading the installed program, prompt "Application not installed"

When upgrading, a small amount of software will appear, so you can only uninstall the old version and install the new version;

7. Check Settings-Development-Allow Simulation Location, and it will be OK;

8. Connect the mobile phone to the computer, then open 9 1 mobile assistant, install an application casually, and select the installation path as the memory of the mobile phone;

9. Some software signatures have been changed, so they cannot be cover the installation. Just remove and reinstall a new version.

10, directly restore the factory settings.