windows phone lumia 1020 - video app dysfunctional. Help?

[Windows Central Question]

video not suddenly no longer working. Using camera button or app. everything is fine except after tapping the screen or using the camera button the counter stays at zero. I have about 7 gb space left, battery is fine, foto mode is excellent. Tapping screen or pushing physical button won't start the recording. Tapping the screen focuses and leaves a grey circle on the screen but nothing else happens after that. Any ideas?