Unity Editor running 2 instances per 1 project from i started project till end.

I used unity few months with this settings, nothing changed.

But today when i started unity and made new project unity runned like this.

It has 2 editor instances. One have main screen and other one is White or Black only screen.

When i used some things which need to pop-up window like New Scene, the 2 editor is randomly changed with each other. And when i turned off the useless instance, both instances were quited. And they have just 1 process.

I reinstalled whole Unity Hub and Unity and downloaded 2~3 unity versions but still happening and so annoying.

Can i get a solution for this?

 

I had this problem too, it's easy really, you just have to change the layout to default, you can find the layout button on the top right corner of unity editor