Problems with system update to WP4.0

About 3 months ago, I made a system update to WordPress 4.0, but it caused some problems on the theme running.
Problems are divided in 2 parts: widgets edition and pages/articles edition.

In the edition of widgets ( in Presentation > Widgets ), I can’t update them or create new ones, because they are blocked.

In the edition of pages/articles I find myself with several errors:
– When I want to create or update a slideshow (in a page or article) it’s not allowed to insert or switch images. This seems to me being the biggest error, in this part. For example when I create a new article with a slideshow, it will automatically appear at the front-end as ” breaking news ” and it’s showed with the first picture from the slideshow. As I can’t create a slideshow, it won’t appear with any image as last news in the front-end;
– Also in this part: I can’t add multimedia contentes automatically on the page editor. For example , if I want to insert an image I have to get the image’s url and insert it into the HTML editor; When I create a new article I can’t insert tags; It’s not allowed to edit the link from a page; I can’t preview a page/article when I’m editing them.

Is there anyone who can help me to solve these problems?

Best Regards.

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