Got it sorted .. in case someone else comes across this thread here’s what i found:-
1.In your post editor down in the right column at the bottom you’ll find ‘featured image’ make sure your pic is at least 300×300
2.In theme options/Blog check the thumbnail place holder
3.Try the ‘image’ option checkbox again in your post editor page on the right, although i didn’t need this in the end and returned the setting to standard.
Hope it’s of some help
