Errors on Google structured data testing tool

Thanks a lot for your quick answer.

So I tried the dev version, it resolved the issue.

Now the Google structured data test is OK:
https://bio-transition.com/wp-content/uploads/2015/10/structured-data2.png

Just I do not understand what does it mean “you will also need to set feature image to the post.”? And how to do it? Do I really need to manage the images? They are not missing …

Finally last point, I noticed that there are two articles url on the structured data test: the standard one and the other one as “https://bio-transition.com/post-ratings-1476”. Should it be like this? or should we get only one article on test?

Thank you very much for your answers.

Best regards,
Cédric.

Ok thank you very much Lester.
Really great support!