Why I can't scan the Whatsapp QR from my inbuilt whatsapp scanner? My whatsapps apps has upgraded to version 2.12.94 and now i am no longer able to scan the web QR code from my whatsapp app inbuilt scanner. 

The code is displayed from the web whatsapps but while using the mobile whatsapp to scan the code, the mobile(HTC M8 Android 5.0.1) and PC is not being paired.

Thanks to provide for a solution.
Not sure if following will Answer your question as exact cause is unknown, but you may try few options.


You must use the latest version of Chrome, Firefox, Opera or Safari web browser to use WhatsApp Web. Other browsers such as Internet Explorer are not supported.
you have to scan the QR-Code with the scanner that is built in WhatsApp. Not with some 3rd-party scanner-app
Make sure there is no adware such as "Superfish" that came with some devices.
Make sure you holding the device correctly enough for the QR scanner to work.
Just like using WhatsApp on your phone, you must have a strong and stable internet connection on your computer to use WhatsApp Web, so make sure your computer's Internet connection is active.
If you use WhatsApp Web on a managed Wi-Fi network, such as at your office or university campus, your network might be configured to block or limit connections to WhatsApp Web.
You may try REFRESH the page and if problem still persist, just try Logout and Login.