eventually i can make the problem more clear in order to get help.
since yesterday it worked like this: in the top menu the section blog referred to articles filed under category "blog" so the domain was: http://www.dennisoellig.com/category/blog/
now, it redirects to the domain http://www.dennisoellig.com/blog-2/ and i dont know how to change it back to where it was.
i would really appreciate if someone could give me a guess on how to solve my problem.
thank u