I'm unable to open new tab. This problem appears after upgrade Opera, Occurs very often when I try to press button on the top of the screen. There is an empty (death) sector that I'm not able to click. I have highlighted on red color:

Top of the button is a most frequent part of it. Please, revert old style button ASAP.

try re-open your browser,

This is Bug DNA-100196. It's got decent priority, but still hasn't been fixed yet.

Where to reach a bug list?

Using Opera maximized, users often use mouse in simplified way - move cursor to top of the screen (you don't need precise muscle movement for this) and hit tabs or buttons. Tabs can be switched this way, search and window buttons too - but new tab button is not clickable at top of screen.

As a matter of fact, there's a setting to remove the upper space above the tabs for this exact same reason: with Opera maximized, if you have that space you can't change tabs by clicking on that line: you need to go down a few pixels. Exact same thing now happens with the + button.

Colour me curious, but is this an issue - does not the + symbol itself work in creating a new tab?

This works of course, but this is not the problem.

Maybe my layout is different to others', but with my taskbar at the top ...

Then you can't see problem for 'normal-layouted' uers and their habits

Using Opera maximized, users often use mouse in simplified way - move cursor to top of the screen (you don't need precise muscle movement for this) and hit tabs or buttons. Tabs can be switched this way, search and window buttons too - but new tab button is not clickable at top of screen.

Patiently waiting.

I've lost hope to solve this problem.