Need Help With Skype Problem

[Rinsun]

This is happening only with the Skype app from the Windows Store.There is no problem with the desktop app. Skype calls are working normally there and Skype detects the High Definition Audio Device.
When I go for Skype call in the app, the call ends and there is a notification 'Call failed, a problem with your playback device.'
When I go to settings in the app, I see a problem just with the speakers only. The microphone is working.
Skype settings show the following:
Audio, Speakers:
'No Device Found.
Skype can't find a speaker attached to your device.'

Drop-down does not allow selection of any device in case of speakers.
I have Skype version 11.19.856.0.
And the latest Windows 10 OS, build 15063.540
I have updated the drivers for High Definition Audio Device, though they were the latest versions.
I had used the Skype Store app on Saturday(2nd Sept), that is not even a week ago when it was fine.
What happened in between? The Skype app got an update on 8th Sept and I faced the problem on the 9th.
I had posted about this problem in the Windows 10 forum but did not get any response, so I posted it here in the hope that somebody might respond.
I would be glad if someone helps me with this problem.
Thanks in advance!