Hardeep, thanks for the prompt answer. You are right. Since I use a custom theme, this “featured image” option was not available for my posts. I solve it by installing another plugin (Quick Figured Images) so I can define a image for the posts and now its working fine. Thanks a lot.
Hi Hardeep. After an hour I figured it out. The page I was trying to add the block was one of the oldest created in my site and the author was still “admin”. After I changed the author to my name, the block worked fine.
Sorry for the stupid mistake and thank you very much for the prompt answer.
By the way, the plugin is great. I will give it a 5 stars.
I do not know if that is possible, but this thread can be deleted or closed.