Featured product problem

Round about the time when WP upgraded to 4.0.1 the bottom half of my home page became invisible. (Links were still there as cursor changed when hovering over them.) After much trial and error it seems to be a problem with the Featured Products widget, which has worked fine for ages. That, along with anything below that, becomes invisible. Move it to the disabled (left) side and the rest becomes visible again!

I have tried re-installing the theme but nothing changed. I am running a Virtue Premium child theme. I have emptied caches on the server and on my 3 laptops but still I cannot get FP to work. At the time it went wrong I was adding a new page. That page works fine.

That WP upgraded just then may be a coincidence. I have no way of telling.

Any advice on how to repair the FP feature would be great.

contemporaryenergy.co.uk

Thanks, Patrick