If you can't install the software, don't worry. Try the following: 1. Search for "foreign application" or "install unknown application" directly in the search bar at the top of the mobile phone settings. If which application is allowed to install the software, turn on the switch of the corresponding application. 2. Maybe the memory of the mobile phone is full. It is recommended to clean up the mobile phone garbage and leave enough space in the memory. 3. The version of the installed software is lower than the existing version, or it is caused by software compatibility problems. Please change to another version or download and install other software again. 4. If you didn't download the software in the Software Store application, it is recommended to delete the software and try again by searching for the downloaded software in the Software Store application. 5. Please confirm whether your mobile phone has obtained ROOT and other permissions to change the stability of the mobile phone system. If yes, please back up the data and install it after brushing the machine in the customer service center. Due to the change of WeChat policy, all versions of WeChat no longer support Android models below 5.0. You can go to the phone settings, click on the phone to check the phone version number ~