I have iPhone 5S recently upgraded to IOS 10.3.3 (14G60) and Zoiper version 3.14.
When I tap on QR Reader a white screen appears with only one option at the bottom of the screen, "cancel" and it is not able to scan the QR to configure my VoIP account.
I have checked iPhone & Zoiper settings and the Zoiper app is able to use the camera.
The camera is working fine also.
Thank you
Harry.