WordPress admin inteface acting weird since 4.0

I’ve been having a lot of issues since update 4.0 was out, i even wonder what was wrong with 3.9. Nevertheles the interface it acting very weird and it drive pe crazy all the time i try to write a new article.
For exemple if try to add a photo, as i did in 3.9 just dragging the photo into the page and a windows appeard, now it just open the photo separately with the local adress from my computer and it deletes what eve writen because it doesnt save automaticaly like before from time to time.
Second everytime i save or upload a photo throught media, or saving as draft or anythng i press i get a pop out asking are you sure you want to exit? ( navigation confirm), even when i publish. It used work flawless, and didnt have any problem before 3.9. I’ve been using chrome browswer as before, but i experience these issue in opera and internet explor aswell and those are only the ones. It seems the interface is not working anymore.
I tryed reinstaled the last version but still the same issue.
I consider mooving my site from the platform, but is my last sollution, because i build it on wordpress and will be chalenging for me to change now.