Can't open level blueprint editor

Hello!

So when I try to “Open level blueprint” it loads, but when the loading screen is done it closes and UE4 (4.9.2) doesn’t show anything else.
I look on my windows screen and see that UE4 haves a new tab called “level blueprint editor”, when I click on it it just returns to UE4 editor (same screen as from the start.
I’ve not done any blueprints myself, just imported ThirtPerson.
When I create new tutorial projects, the same happens in them.

I’ve searched this and found no answers.

Thank you, Lukas

I found it!

Window > reset layout.

Thank you man you save my project i have same problems so THANK YOU !!