How to fix rich snippets error on asteroid theme?!

Hi,

if i log into my google webmaster tool account, i see in the section “structured data” the following two errors many times:

Warning: Missing required field “updated”
Warning: Missing required hCard “author”

Before i post here, i have checked up the internet and found this post: LINK

I could not solve this problem, what do i need to change on the asteroid theme? Thanks