Experience on Applying for Google Adsense: "Valuable inventory: Under construction"

I managed to have my first Google AdSense approved not too long ago. It was quite a challenge. I encountered a problem with "Valuable inventory: Under construction". It was a bit frustrating when I kept getting rejected over and over due to this problem. Google AdSense did not elaborate clearly what exactly was wrong with my website so I had to do a lot of trial and error in order to fix the