An update installed last week & it was stuck on the lock screen. I googled & was able to reboot the phone & everything seemed ok. It was acting funny today so I rebooted it & it just kept rebooting over & over. Finally stopped & I was texting & calling people. Set the phone down & it rebooted itself & now is on this lock screen. There's a little black box in the upper left corner with red letters that say "Secure Check Fail: Modem" I really need my phone & I don't know what to do. My carrier is Verizon if that makes a difference. TIA. ~ Linda