Can’t switch between sites

The plugin was working properly but suddently it stopped. I’m trying to fix it. It seems that any version (spanish nor english) doesn’t know about the other. In the posts/pages I see:

“You should define at least another blog in a different language in order to have some benefit from this plugin!”

But in the settings of the plugin I don’t see anything about connect both versions.

The page I need help with: [log in to see the link]