I rooted my att s4 fewyears back with KINGROOT PC, cause just too many apps, 90% of which I would never use. Few months back it bootlooped so I reflashed 4.2.2 back to 5.0 then it Ota to 5.1 . I d/l the KR app and it worked fine but I rebooted right after and it lost root. So I used the KR PC method and got root but after using sume it lost root again, so I've tried over and over now but I can not get KINGROOT to get root access for me anymore. After using the app I couldn't get the app to reinstall so I restored my phone and then it was able to have PC ver. Work once but wouldn't work after that. Was wondering if att updated security to stop being able to root . I'm thinking about flashing 442 back on it and trying to root with chainfire method since I can't install trwp or any other backup to root with but kingroot is unable to root the s4 anymore. Should be a law to make att give back our phones.