After using SEOquake to analyse my blog article, it gave me an error saying:

This page utilizes Microformat markup, but some tags are using incorrect case. Please validate your markup with the Google Structured Data Testing Tool.
You can validate your markup with the Google Structured Data Testing Tool.
vcard, hreview

The next thing I did is use the Google Structured Data Testing Tool to test that particular single article's error and it surely showed me what are the errors and warnings regarding the structured data of my written article. As you can see in the image below, I got 3 errors and 3 warnings.



And these errors and warnings are the following as seen in the image below:

a. A value for the author field is required.
b. A value for the image field is required.
c. A value for the publisher field is required.

And you can also see the warnings. But let us just focus in how to solve the author error or "A value for the author field is required".



STEPS:

1. Go to your Blogger Layout.

2. Find the main wrapper (Blog Posts - Blog Posts gadget) and click Edit.


3. Find "Post Page Options", check the "By: author name", and then click the Save button.


4. Now, go back to Google Structured Data Testing Tool and refresh the page.


5. The author section is now fixed and the message "A value for the author field is required" was gone and being replaced by @type - Person, and name - Tam.

6. Done!

If you have some thing to say or ask regarding this tutorial, please leave a comment below. Thanks!