Can't add new post

Hello,

maybe you have solutions for this problem:
today I upgraded the WP version from 4.3.0. to 4.3.1., then I just want to create a new post. Then I realised when I go to New Post page, the is nothing in the fields Title and Text – as always when I create a new post. BUT the entry’s URL, featured image, post date, categories, featured picture are not empty, they are belonging to my earlyer post. And when I go to publish button on the New Post page, it updates that post what’ picture, categories, URL etc was there before.
Here is my page: http://www.fesztblog.hu
Here is a screenshot about the problem: http://i57.tinypic.com/opnxwz.jpg

Do you have any solutions for this?
Thank you so much!