Google Structured Data generates lots of errors

I was recently looking into my Google Webmaster tools when I discovered there are a lot of Structured Data errors. Most of them are:
– Warning: Missing required field “entry-title”.
– Warning: Missing required field “updated”.
– Warning: Missing required hCard “author”.

I’ve been Googling quite a bit and it looks like this problem is happening to a lot of people that use WordPress and that it all started early December 2013. Since these errors might negatively influence Google rankings, I’d like to solve this problem.

I’ve found this solution that seems to work for a lot of people, but unfortunately the code that is mentioned in that article cannot be found in the single.php file of the Spun-theme.

Some of the content-***.php files do contain code similar to the code that is mentioned in that article but I don’t really know what to change where.

Anyone with experience on this?

Thanks,
Cheers,
Roel