Found two bugs in camera-ui2:

Open camera
Open 'General settings' (rectangle icon on the lower left on main screen)
Change 'Show captured image' setting to something else
Click save
Image count (number on the left) now is 0 and 'General settings' icon has become a striked out microphone (mute?)
Take an image/record video -> "Memory full. Unable to save image."

Restoring the original settings for 'Show captured image' does not fix that. Cannot choose internal storage for saving images (drop down is disabled).

Only way to fix the problem was to insert a microSD card and restart camera application, then go to 'General settings' and choose 'Internal Storage'.

Bug is reproducible every time.

Second one:

While 'No' is selected for 'Show captured image' setting camera-ui does not save captured images.