hi,
when double clicking the home button on an iphone, and closing background apps (flicking up) if you receive a phone call when in this screen…phone freezes! i am unable to press the home button to return to desktop, i am unable to close (flip up) any of the remaining background apps.
phone is not responding to the power button, phone is not responding when connected to iTunes via cable.
anyone had this happen?
Good Lord, a phone call, just like 1999! Slightly tongue in cheek I’d have to say that the phone “app” of my iPhone is one of the least used!
Did you get it working again? Try holding down the power and home buttons together if not, otherwise a trip to the Genius Bar might be needed.
Ha Ha 
yeah did a hard reset. I actually use my iPhone a lot for voice calls…i’m old 
Was it a once off, or have you managed to repeat it deliberately?
…2017…?
Pretty sure it’s the iOS engineers’ way of telling you to stop wasting your time closing background apps. 