iPhone Lockscreen Unresponsive: How To Fix It?

Many iPhone users reported that their device’s Lockscreen becomes unresponsive, they are unable to unlock their device. Most of the users who encountered this issue had older iPhones like, iPhone 4, 4s or 5.

How To Fix It ... !
Launch an App Using SiriIf you haven’t enabled Siri, go to Settings →tap on General → tap on Siri and turn it on.

Press and hold on the Home button then tell Siri to launch an app. This trick has worked for many users.
Restart your iPhonesome minor issues can easily be fixed by restarting your device.
Power down your device , Once your iPhone restarts, unlock your device as usual. It should be alright.