that's because the certificate in the software package doesn't match your mobile phone, because the certificate is made according to the serial number of your mobile phone, and you can't install it unless it is made by your mobile phone serial number. General certificates are authorized, 13 permissions are universal, and personal certificates are 17 permissions, but it is very difficult to do 19 and 2 permissions, so some people simply make software to crack permissions, find Lexun in the cool mobile phone station of UC browser, and then register an account in Lexun Forum. Each account can apply for five certificates with 17 permissions, all of which are free. If you crack this software there, you will not be bothered by certificates after cracking it, or directly.