phone keeps lagging sometimes while using youtube..it freezesfor a couple of minutes notging works..no button responds..cant even restart the phone. and qfter a coupke of minutes a popup appears "system UI stopped". this has happened 3 4 times with m...

During using whatsapp,swipe type didnt worked and the keyboard froze even after numerous attempts to go back to home screen initially it didnt worked..after homescreen appeared but keyboard was not disappering(refer attached file).Please fix asap.