Everytime When I post item of blog Window close

I can post item of blog. but I have question. When I at this window. I put title and select blog. then when I click item. this window close automaticuly. Could you teach me solution please?

What browser/operating system are you using?

Do you mean that once you click “Item” for the page template, the dialog closes automatically?

Hi. Thank you for answering me.
I use Windoes 10 64 bit. and I use newest Grav verison and theme is twentyfifteen.

And. YES. that happend my grav.

so I have click [Add] button again. All info I just typed there was keep at smaill window.