Translate "posted on" in blog posts

After I upgraded to version 4.8 I noticed that the translated text is back in English. The url is https://www.digitalkreativitet.no/ I have translated everything into Norwegian before. On blogposts it says: Posted on 11. juni 2017 by Marianne — No Comments ↓ Continue reading Edit Posted in ... | Leave a reply When I click on a blogpost it says: Previous Next Posted on 1. juni 2017 by Marianne — No Comments ↓ This entry was posted in BlåStriper by Marianne. Bookmark the permalink. Edit On pages it is correct - exept the Edit. When I search for something it says: SEARCH RESULTS FOR When I choose a category it says: CATEGORY ARCHIVES But when I use the archive button, it says the month in Norwegian. I have checked the new .po-file, but I can't find these things, and I don't know how I add new words.