No one page of my site is indexed, why?

After a long time later, I finally got the answer from BING, answering my question.
In this email it was said that my site is misunderstanding some of the "Things to Avoid" guidelines.

But unfortunately they didn't say exactly WHERE the problem is, so how am I going to find a problem that isn't specified exactly in the guidelines? I have a lot of posts and how to find the correct source of the problem?
Sad. Anyway, the site is on Google, Yandex and outside of BING...