Bug or not after updating Nirvana?

I just updated the theme Nirvana (just as usual), but discovered that when I did this almost the entire header disappeared (can only see the top of it) and that the side titles appears in the top left and that all the fonts on the whole page and in blog posts has become bigger and that all text on all of my pages, previously correct and divided into nice little paragraphs, now is without paragraph division.

I’ve never had a problem before with the Nirvana theme and have always been very happy with this.

Should I really need to change the text of each blog post and on each page or is there anything I can do to restore? (Besides using WP-Rollback that isn’t tested with my version of WordPress).

I’m not technical and can not change the codes. So I wonder if someone has had the same problem? What did you do to get it right? Are there any known problem with some plugins like Page Builder from SiteOrigin or Foo Gallery?

Website: www.ekohyllan.nu