Thumbnail image no longer appearing

Hello,

I liked the theme very much but when switching to V1, the thumbnail images do no longer appear: http://rassemblement-grenoble.net/
I changed the image size but it does not fix it.

Unfortunately, it is no longer possible to post on the author page. I am ready to add the pro version to fix this but here also it is impossible to create an account. I wrote to the auuthor but no reply so far… I am using the latest version 1.4

Thanks for your help,

Benjamin