stuck on starting on sony screen

when i m trying to use flashtool my phne was stuck on sony screen i try to flash again with flash tool but it show following msg\

10/056/2015 00:56:29 - INFO - Flashing finished.
10/056/2015 00:56:29 - INFO - Please unplug and start your phone
10/056/2015 00:56:29 - INFO - For flashtool, Unknown Sources and Debugging must be checked in phone settings
plz help me proper soltution