[xwiki-devs] Problems with the Blog

Hi! I have a big problem with my blog-function in my Wiki. I've delete all example posts over the wiki function and the blank categories over my SQL. My problem now is, that I cannot make new posts in the standard categories. If I click on "Create Blog Post", I can set the posttitle Name. That is normal... But then I click on "Create": I get the error message "This is not an article". What should I do? I really need the blog. I hope you can help me... Thanks for your help! Torben