blogger popular post thumbnail not showing?

How to fix Popular Posts Gadget not displaying all thumbnails on blog spot:

1. download the image that is not showing thumbnail & remove it from the blog entry

2. rename it to something simple: like" a.jpg" or "b.png" etc...

3. re-upload it.

Thumbnail should be showing from this point, if not ... repeat the steps and try to converting non-jpg images to jpg.

Most problematic images for me are either png or images with weird long names.