missrt

My post thumbnails are no longer generating when I share via Facebook share or paste the link to Facebook. It’s all text; no image.

The only changes I can think of are the WP 3.4 upgrade and I switched from PC to a Macbook Air. Do you have any thoughts on the possible problem and solution?

Also would the downgrade resolve any issues caused by the upgrade?

I am assuming the answer is no since I don’t know how to and did not do that prior to upgrade. Would my server host have a pre-upgrade database backup possibly?