can't scan whats app qr code !!! topic

hi guys
i installed whatsapp the last version and the whatsapp web option showed up
and after i click on ok , i got it and try to scan the code nothing happens
its still change the code on my pc and whatsapp qr scanner dosent do any thing
i tried to scan the code with other qr scanner and its works fine
what is the problem nw and how could i solve it ?:(