drupal 7 blog missing

Hi
I have drupal 7 blog site. But I want to migrate to drupal 8, it shows source blog destination missing.
What can I do
I continued, but then it shows only title but not body.
Interesting thing is that, in phpmyadmin, I can see body content, plz help

Drupal version: 


Source: https://www.drupal.org/taxonomy/term/37/feed