If you read The thumbnails on the new tab page are missing - how to get them back, does this help you?

Do you at least see empty slots with the URL below them?

Does it help if you drag a site that you've visited in one of the slots?

The thumbnails on the about:newtab page are generated from the cache, so if the page is not in the cache or otherwise can't be rendered as a PNG image then you will get an empty box.
Do not use Clear Recent History to clear data when you close Firefox.
If there is no history then you get an about:newtab page with empty boxes.

I see outlined boxes with urls, yes.. but no image is rendered of the page.

I have history is cache, about 7 days worth. I do not clear cache, as I like to be able to find pages/sites I've stumbled on and forgot to bookmark. If cache is cleared, the pages that display on about:newtab should still be able to show images of the page. I visit these sites multiple times Daily, one after the other.

Still no "png" of the page..

See also:

• bug 756881 - New tab thumbnails not displayed (or old images displayed) for Facebook, Twitter (sites using Cache-Control no-store)

(please do not comment in bug reports)

The sites I have pinned to the New Tab (about:newtab) are not Facebook, Twitter, or anything similar; Same of the sites I have pinned are Namecheap.com, kukuklok.com, Lifehacker.com, USAA.com, Google.com, Pinterest.com, Paypal.com