When ever I try to place a call or access Viber, why does the screen go black?

[Windows Central Question]

Nokia lumia 630 Dual Viber App Issue

Hello! I'm facing an issue with my viber app on my lumia 630 dual... Whenever i place a call or try to access viber on screen button (e.g. loudspeaker) the screen goes black and unable to access any of the button. Due to the issue not even able to end the call.

Help my to resolve the issue.
Thanks

 

[anon8959613]

Re: Nokia lumia 630 Dual Viber App Issue

​Lumia 630 doesnt have a proximity sensor .
so it relies on touchscreen to lock the screen during calls.
on a normal call, the upper half of the screen does this for you.
but for viber app the entire screen is sensitive.
you cant do anything about it. (tell the other person to hangup first )
i also own a lumia 630.
same thing applies for skype.